As of June 30, ~~2017~~,2022, the aggregate market value of Ameren Corporation’s common stock, $0.01 par value, (based upon the closing price of the common stock on the New York Stock Exchange on June 30, ~~2017~~)2022) held by nonaffiliates was ~~$13,230,607,078.~~$23,231,496,514. All of the shares of common stock of the other registrants were held by Ameren Corporation as of June 30, ~~2017~~.2022.

The number of shares outstanding of each registrant’s classes of common stock as of January 31, ~~2018~~,2023, were as follows:

Statements in this report not based on historical facts are considered “forward-looking” and, accordingly, involve risks and uncertainties that could cause actual results to differ materially from those discussed. Although such forward-looking statements have been made in good faith and are based on reasonable assumptions, there is no assurance that the expected results will be achieved. These statements include (without limitation) statements as to future expectations, beliefs, plans, projections, strategies, targets, estimates, objectives, events, conditions, and financial performance. In connection with the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995, we are providing this cautionary statement to identify important factors that could cause actual results to differ materially from those anticipated. The following factors, in addition to those discussed within Risk Factors under Part I, Item 1A, of this report, and elsewhere in this report and in our other filings with the SEC, could cause actual results to differ materially from management expectations suggested in such forward-looking statements:

New factors emerge from time to time, and it is not possible for management to predict all of such factors, nor can it assess the impact of each such factor on the business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained or implied in any forward-looking statement. Given these uncertainties, undue reliance should not be placed on these forward-looking statements. Except to the extent required by the federal securities laws, we undertake no obligation to update or revise publicly any forward-looking statements to reflect new information or future events.

Ameren, formed in 1997 and headquartered in St. Louis, Missouri, is a public utility holding company whose primary assets are its equity interests in its subsidiaries. Ameren’s subsidiaries are separate, independent legal entities with separate businesses, assets, and liabilities. Dividends on Ameren’s common stock and the payment of expenses by Ameren depend on distributions made to it by its subsidiaries.

Below is a summary description of Ameren’s principal subsidiaries ~~including~~– Ameren Missouri, Ameren Illinois, and ATXI. Ameren also has other subsidiaries that conduct other activities, such as ~~the provision of~~providing shared services. ~~Ameren evaluates competitive electric transmission investment opportunities as they arise.~~ A more detailed description can be found in Note 1 – Summary of Significant Accounting Policies under Part II, Item 8, of this report.

For additional information about the development of our businesses, our business operations, and factors affecting our results of operations, financial position, and liquidity, see Management’s Discussion and Analysis of Financial Condition and Results of Operations under Part II, Item 7, ~~of this report~~ and Note 1 – Summary of Significant Accounting Policies and Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report.

Ameren has four segments: Ameren Missouri, Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Transmission. The Ameren Missouri segment includes all of the operations of Ameren Missouri. Ameren Illinois Electric Distribution consists of the electric distribution business of Ameren Illinois. Ameren Illinois Natural Gas consists of the natural gas business of Ameren Illinois. Ameren Transmission is primarily ~~composed~~consists of the aggregated electric transmission businesses of Ameren Illinois and ATXI.

Ameren Missouri has one segment. Ameren Illinois has three segments: Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Illinois Transmission.

An illustration of the Ameren ~~and Ameren Illinois’~~Companies’ reporting structures is provided below. For additional information on financial reporting segments, see Note 1 – Summary of Significant Accounting Policies and Note 15 – Segment Information under Part II, Item 8, of this report.below:

The rates that Ameren Missouri, Ameren Illinois, and ATXI are allowed to charge for their utility services significantly influence the results of operations, financial position, and liquidity of these companies and Ameren. The electric and natural gas utility industry is highly regulated. The utility rates charged to customers are determined by governmental entities, including the MoPSC, the ICC, and the FERC.

The MoPSC regulates rates and other matters for Ameren Missouri. The ICC regulates rates and other matters for Ameren Illinois. The MoPSC and the ICC regulate non-rate utility matters for ATXI. ATXI does not have retail distribution customers; therefore, the MoPSC and the ICC do not have authority to regulate ATXI’s rates. The FERC regulates Ameren Missouri’s, Ameren Illinois’, and ATXI’s cost-based rates for the wholesale transmission and distribution of energy in interstate commerce and various other matters discussed below under General Regulatory Matters.

The following table summarizes the key terms of the rate orders in effect for customer billings for each of Ameren’s rate-regulated utilities as of January 1, 2023, except as noted:

Ameren Missouri, Ameren Illinois, and ATXI must receive FERC approval to enter into various transactions, such as issuing short-term debt securities and conducting certain acquisitions, mergers, and consolidations involving electric utility holding companies. In addition, Ameren Missouri, Ameren Illinois, and ATXI must receive authorization from the applicable state public utility regulatory agency to issue stock and long-term debt securities ~~(with maturities of more than 12 months)~~ and to conduct mergers, affiliate transactions, and various other activities.

Ameren Missouri, Ameren Illinois, and ATXI are also subject to mandatory reliability standards, including cybersecurity standards adopted by the FERC, to ensure the reliability of the bulk electric power system. These standards are developed and enforced by the NERC, pursuant to authority delegated to it by the FERC. Ameren Missouri, Ameren Illinois, and ATXI are members of the SERC. The SERC is one of six regional entities and represents all or portions of 16 central and southeastern states under authority from the NERC for the purpose of implementing and enforcing reliability standards approved by the FERC. Ameren Missouri is also a member of the MRO, which is also one of the six regional entities and represents all or portions of 16 central, southern, and midwestern states, as well as two Canadian provinces, under authority from the NERC. The regional entities of the NERC work to safeguard the reliability of the bulk power systems throughout North America. If any of Ameren Missouri, Ameren Illinois, or ATXI is found not to be in compliance with these mandatory reliability standards, it could incur substantial monetary penalties and other sanctions.

Under ~~PUHCA~~the Public Utility Holding Company Act of 2005, the FERC and ~~any~~the state public utility regulatory ~~agency~~agencies in each state Ameren and its subsidiaries operate in may access books and records of Ameren and its subsidiaries that are found to be relevant to costs incurred by Ameren’s rate-regulated subsidiaries that may affect jurisdictional rates. ~~PUHCA 2005~~The act also permits the MoPSC and the ICC to request that the FERC review cost allocations by Ameren Services to other Ameren ~~companies.~~subsidiaries.

Operation of Ameren Missouri’s Callaway ~~energy center~~Energy Center is subject to regulation by the NRC. The license for the Callaway ~~energy center~~Energy Center expires in 2044. Ameren Missouri’s hydroelectric Osage Energy Center and pumped-storage hydroelectric ~~energy center and~~ Taum Sauk ~~pumped-storage hydroelectric energy center,~~Energy Center, as licensed projects under the Federal Power Act, are subject to FERC regulations affecting, among other aspects, the general operation and maintenance of the projects. The licenses for the Osage ~~hydroelectric energy center~~Energy Center and the Taum Sauk ~~pumped-storage hydroelectric energy center~~Energy Center expire in 2047 and 2044, respectively. Ameren Missouri’s Keokuk ~~energy center~~Energy Center and its dam inon the Mississippi River between Hamilton, Illinois, and Keokuk, Iowa, are operated under authority granted by an Act of Congress in 1905.

For additional information on regulatory matters, see Note 2 – Rate and Regulatory Matters, Note 9 – Callaway Energy Center, and Note 14 – Commitments and Contingencies under Part II, Item 8, of this report.

~~Certain~~Our electric generation, transmission, and distribution and natural gas distribution and storage operations must comply with a variety of ~~our operations are subject to federal, state, and local environmental~~ statutes and regulations relating to the protection of the ~~safety~~environment and human health ~~of our personnel, the public,~~ and ~~the environment.~~safety. These environmental statutes and regulations are comprehensive and include ~~requirements relating to identification, generation,~~the storage, handling, transportation, disposal, recordkeeping, labeling, reporting, and emergency response in connection with hazardous and toxic materials; safety and health standards; and environmental protection requirements, including standards and limitations relating to the discharge of air and water pollutants and the management of waste and byproduct materials. Failure to comply with these statutes or regulations could have material adverse effects on us. We could be subject to criminal or civil penalties by

Ameren owns an integrated transmission system that is composed of the transmission assets of Ameren Missouri, Ameren Illinois, and ATXI. Ameren also operates two MISO balancing authority areas: AMMO and AMIL. ~~During 2017,~~The AMMO balancing authority area includes the load and most energy centers of Ameren Missouri, and had a peak demand ~~was 7,814 megawatts~~of 7,584 MWs in ~~AMMO~~2022. The AMIL balancing authority area includes the load of Ameren Illinois and ~~8,877 megawatts~~certain natural gas-fired energy centers of Ameren Missouri, and had a peak demand of 8,510 MWs in ~~AMIL.~~2022. The Ameren transmission system directly connects with 15 other balancing authority areas for the exchange of electric energy.

Ameren Missouri, Ameren Illinois, and ATXI are transmission-owning members of the MISO. Ameren Missouri is authorized by the MoPSC to participate in the MISO ~~through May 2020. The previously required~~for an indefinite term, subject to the MoPSC’s authority to require future proceedings if an event or circumstance occurs that significantly affects Ameren Missouri’s position in the MISO. Ameren Illinois’ election to participate in the MISO is subject to the ICC’s oversight. In July 2022, the ICC issued an order requiring Ameren Illinois to perform a cost-benefit study ~~related to Ameren Missouri’s~~of continued participation in the MISO ~~as required periodically by the MoPSC~~compared to participation in PJM Interconnection LLC, another RTO, and ~~originally expected to be filed in 2017, was deferred upon approval of the MoPSC. Ameren Missouri expects to~~ file the ~~periodic cost-benefit~~ study ~~in 2020, based on~~by July 2023. For additional information regarding the ~~deferral granted by the MoPSC.~~July 2022 ICC order, see Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report.

Ameren Missouri sells nearly all of its capacity to the MISO and purchases the capacity it needs to supply its native load sales from the MISO. In the April 2022 MISO capacity auction, Ameren Missouri’s generation resources exceeded its native load capacity requirements. Ameren Illinois purchases capacity from the MISO and through bilateral contracts resulting from IPA procurement events. In August 2022, the FERC issued an order approving changes to the annual MISO capacity auction. Historically, the auctions were designed to cover annual peak demand plus a target reserve margin. Beginning with the April 2023 auction for the June 2023 to May 2024 planning year, auctions will include four seasonal load forecasts and available capacity levels and will be designed to cover each season’s peak demand plus a target reserve margin. The seasonal auction structure will help to address variability in resources as the MISO begins to rely more heavily on renewable generation.

Ameren Missouri’s electric supply is primarily generated from its energy centers. Factors that could cause Ameren Missouri to purchase power include, among other things, energy center outages, the fulfillment of renewable energy ~~portfolio~~ requirements, ~~the failure of suppliers to meet their power supply obligations,~~ extreme weather conditions, the availability of power at a cost lower than its generation cost, and ~~absence~~the lack of sufficient owned ~~generation.~~generation availability.

Ameren Missouri files a long-term nonbinding ~~20-year~~ integrated resource plan with the MoPSC every three years. The most recent integrated resource plan was filed in September ~~2017, includes~~2020 and changed in June 2022 to include certain modifications to Ameren Missouri’s preferred approach for meeting customers’ projected long-term energy needs in a cost-effective manner while maintaining system ~~reliability.~~reliability and customer affordability. The ~~plan targets cleaner and more diverse~~preferred approach includes, among other things, the following:

The addition of renewable and natural gas-fired combined cycle generation facilities is subject to obtaining necessary project approvals, including FERC approval and the issuance of a certificate of convenience and necessity by the MoPSC, as applicable. Ameren Missouri would be adversely affected if the MoPSC does not allow recovery of the remaining investment and decommissioning costs associated with the retirement of an energy center, as well as the ability to earn a return on that remaining investment and those decommissioning costs. In connection with the planned accelerated retirement of the Rush Island Energy Center, Ameren Missouri expects to seek approval from the MoPSC to finance the costs associated with the retirement, including the remaining unrecovered net plant balance associated with the facility, through the issuance of securitized utility tariff bonds pursuant to the Missouri securitization statute. The next integrated resource plan is expected to be filed in September 2023.

Ameren Missouri continues to evaluate its longer-term needs for new generating capacity. The need for ainvestment in new sources of energy ~~center~~ is dependent on several key factors, including continuation of and customer participation in energy-efficiency programs, ~~and~~the amount of distributed generation from customers, load growth, technological advancements, costs of generation alternatives, environmental regulation of coal-fired and natural gas-fired power plants, and state renewable ~~portfolio standards,~~energy requirements, which could lead to the retirement of current baseload assets before the end of their current useful lives or alterations in the way those assets ~~operate.~~operate, which could result in increased capital expenditures and/or increased operations and maintenance expenses. Because of the significant time required to plan, acquire permits for, and build a baseload energy center, Ameren Missouri continues to study alternatives and to take steps to preserve options to meet future demand. Steps include evaluating the potential for further diversification of Ameren Missouri’s generation portfolio through

~~See also Outlook~~Missouri law requires Ameren Missouri to offer solar rebates and net metering to certain customers that install renewable generation at their premises. The difference between the cost of the rebates and the amount set in ~~Management’s Discussion~~base rates are deferred as a regulatory asset or liability under the RESRAM, and Analysis of Financial Condition and Results of Operations under Part II, Item 7, Note 2 – Rate and Regulatory Matters, Note 9 – Callaway Energy Center, and Note 14 – Commitments and Contingencies under Part II, Item 8, of this report.earn carrying costs at short-term interest rates. Customers that elect to enroll in net metering are allowed to net their generation against their usage within each billing month.

In Illinois, while electric transmission and distribution service rates are regulated, power supply prices are not. Although electric customers are allowed to purchase power from an alternative retail electric supplier, Ameren Illinois is required to be the provider of last resort for its electric distribution customers. In ~~2017, 2016,~~2022, 2021, and ~~2015,~~2020, Ameren Illinois procured power on behalf of its customers for ~~23%~~28%, 23%, and ~~26%~~23%, respectively, of its total kilowatthour sales. Power purchased by Ameren Illinois for its electric distribution customers who do not elect to purchase their power from an alternative retail electric supplier comes either through procurement processes conducted by the IPA or through markets operated by the MISO. The IPA administers an RFP process through which Ameren Illinois procures its expected supply. The purchased power and related procurement costs incurred by Ameren Illinois are passed directly to its electric distribution customers through a cost recovery mechanism. Transmission costs are charged to customers who purchase electricity from Ameren Illinois and to alternative retail electric suppliers through a cost recovery mechanism. The purchased power, power procurement, and transmission costs are reflected in Ameren Illinois Electric Distribution’s results of operations, but do not affect Ameren Illinois Electric Distribution’s earnings because these costs are offset by corresponding revenues. Ameren Illinois charges ~~transmission and~~ distribution service rates to electric distribution customers who purchase electricity, ~~from alternative retail electric suppliers,~~regardless of supplier, which does affect Ameren Illinois Electric Distribution’s earnings.

~~See Note 13 – Related-party Transactions~~Pursuant to the IETL, Ameren Illinois is required to file a multi-year integrated grid plan with the ICC every four years. In January 2023, Ameren Illinois filed its first multi-year integrated grid plan for the years 2023 to 2027. The plan outlines how Ameren Illinois expects to operate and ~~Note 14 – Commitments~~invest in electric distribution infrastructure in order to support grid modernization, clean energy, energy efficiency, and ~~Contingencies under Part II, Item 8,~~the state of ~~this report for additional information on power procurement~~Illinois’ renewable energy, equity, climate, electrification, and environmental goals, while providing safe, secure, reliable, and resilient electric distribution service to customers. Ameren Illinois’ next multi-year integrated grid plan is required by mid-January 2026.

Illinois law requires Ameren Illinois to offer rebates and net metering to certain customers that install renewable generation or paired energy storage systems at their premises. The cost of the rebates are deferred as a regulatory asset, which earn a return at the applicable WACC. Customers that elect to receive a generation rebate and are enrolled in ~~Illinois.~~net metering are allowed to net their supply service charges, but not their distribution service charges. Effective January 2023, customers that elect to receive energy storage rebates and have not received generation rebates are allowed to net their supply and distribution service charges. By law, Ameren Illinois’ electric distribution revenues are decoupled from sales volumes, which ensures that the electric distribution revenues authorized in a regulatory rate review are not affected by changes in sales volumes.

Ameren Missouri owns energy centers that rely on a diverse fuel portfolio, including coal, ~~(Ameren Missouri’s primary fuel source),~~ nuclear, and natural gas, as well as renewable sources of generation, which include hydroelectric, wind, methane gas, and solar. All of Ameren Missouri’s coal-fired energy centers were constructed prior to 1978. The Callaway ~~nuclear energy center~~Energy Center began operation in 1984 and is licensed to operate until 2044. As of December 31, ~~2017,~~2022, Ameren Missouri’s ~~fossil fuel-fired~~coal-fired energy centers represented ~~17%~~9% and ~~33%~~17% of Ameren’s and Ameren Missouri’s rate base, respectively. The Meramec Energy Center was retired at the end of its useful life in December 2022. Also in December 2022, Ameren Illinois placed a solar generation facility in service, which is one of two pilot solar projects Ameren Illinois is allowed to invest in under the IETL. See Item 2 – Properties under Part I of this report for information regarding ~~Ameren Missouri’s electric generation~~our energy centers.

Ameren Missouri has an ongoing need for coal as fuel for generation, and pursues a price-hedging strategy consistent with this requirement. Ameren Missouri has agreements in place to purchase and transport coal to its energy centers. ~~As of December 31, 2017, Ameren Missouri had price-hedged 88% of its expected coal supply and 99% of its coal transportation requirements for generation in 2018.~~While Ameren Missouri has ~~additional coal supply under contract through 2021. The coal transport~~minimum purchase obligations associated with these agreements, ~~that Ameren Missouri has~~the majority of these agreements are not associated with ~~Union Pacific Railroad and Burlington Northern Santa Fe Railway are currently set to expire at the end of 2019.~~any specific coal-fired energy center. Ameren Missouri burned approximately ~~18.6~~14.5 million tons of coal in ~~2017.~~2022. For information regarding the percentages of Ameren Missouri’s projected required supply of coal and coal transportation that are price-hedged through 2027, see Commodity Price Risk under Part II, Item 7A, of this report.

About 97% of Ameren Missouri’s coal is purchased from the Powder River Basin in ~~Wyoming.~~Wyoming, which has a limited number of suppliers. The remaining coal is typically purchased from the Illinois Basin. ~~Inventories~~Targeted coal inventory levels may be adjusted because of generation levels

The production of nuclear fuel involves the mining and milling of uranium ore to produce uranium concentrates, the conversion of uranium concentrates to uranium hexafluoride gas, the enrichment of that gas, the conversion of the enriched uranium hexafluoride gas into uranium dioxide fuel pellets, and the fabrication into fuel assemblies. Ameren Missouri has entered into uranium, uranium conversion, uranium enrichment, and fabrication contracts to procure the fuel supply for its Callaway ~~energy center.~~Energy Center.

The Callaway ~~energy center~~Energy Center requires refueling at 18-month intervals. The last refueling was completed in ~~December 2017.~~May 2022. The next refueling is scheduled for the ~~spring~~fall of ~~2019. As of December 31, 2017, Ameren Missouri had agreements or inventories to price-hedge all of Callaway’s spring 2019 refueling requirements.~~2023. Ameren Missouri has inventories and supply contracts sufficient to meet all of its uranium (concentrate and hexafluoride), conversion, enrichment, and ~~enrichment~~fabrication requirements at least through the ~~2022~~2026 refueling. ~~Ameren Missouri has~~ f~~uel fabrication service contracts through at least 2022.~~

Missouri and Illinois laws require electric utilities to include renewable energy resources in their portfolios. Ameren Missouri and Ameren Illinois satisfied their renewable energy portfolio requirements in 2022.

In Missouri, utilities are required to purchase or generate electricity equal to at least 5%15% of native load sales from renewable energy sources, ~~beginning in 2017. That percentage will increase to~~with at least ~~15% by 2021,~~2% of the requirement derived from solar energy. The requirement is subject to an average 1% annual increase on customer rates over any 10-year period. ~~At least 2%~~For renewable generation facilities located in Missouri, 125% of ~~each renewable energy portfolio requirement must be derived from solar energy. In 2017, Ameren Missouri met its renewable energy requirements.~~the electricity generated counts towards meeting the requirement. Ameren Missouri expects to satisfy the nonsolar requirement in ~~2018~~2023 with its High Prairie Renewable, Atchison Renewable, Keokuk, ~~energy center~~ and ~~its~~ Maryland Heights energy ~~center, and through~~centers, a ~~102-megawatt~~102-MW power purchase agreement with a wind farm ~~operator.~~operator, and immaterial renewable energy credit purchases in the market. The High Prairie Renewable and Atchison Renewable energy centers are wind generation facilities. The Keokuk Energy Center generates electricity using a hydroelectric dam located on the Mississippi River. The Maryland Heights ~~energy center~~Energy Center generates electricity by burning methane gas collected from a landfill. Ameren Missouri is meeting the solar energy requirement by purchasing solar-generated renewable energy credits from customer-installed systems and by generating ~~its own solar~~ energy at ~~the O’Fallon energy center and at~~ its ~~headquarters building. See Supply of Electric Power above for renewable energy plans incorporated in Ameren Missouri’s integrated resource plan, filed with the MoPSC in September 2017.~~solar facilities.

In accordance with Illinois ~~met the renewable energy requirement. Starting June 1, 2017,~~law, Ameren Illinois is required to collect funds from all electric distribution customers to fund IPA procurement events for renewable energy credits. The amount set by law and required to be collected from customers by Ameren Illinois is capped at $4.58 per MWh. The IPA establishes its long-term renewable resources procurement plans in a filing made every two years. In July 2022, the ICC approved the IPA’s latest long-term renewable resources procurement plan. Based on IPA procurement events that align with the IPA’s plan, Ameren Illinois has contractual commitments of approximately 0.7 million wind renewable energy credits per year and approximately 1.7 million solar renewable energy credits per year. Ameren Illinois has also entered into contracts, ending in 2032, to purchase approximately 0.6 million wind renewable energy credits per year. Pursuant to the IETL, if funds collected from customers are not used to procure renewable energy credits, they would be refunded to customers pursuant to a reconciliation proceeding, the first of which is expected to be initiated after August 2023. Based on amounts collected from customers and renewable energy credit purchases under contract, Ameren Illinois does not expect the first reconciliation proceeding to result in refunds to customers. The IPA is expected to file its next long-term renewable resources ~~for all~~procurement plan in 2023, which, once approved by the ICC, will establish the 2023 and 2024 renewable energy credit procurement targets.

Illinois law also required Ameren Illinois to ~~procure zero-emission~~enter into contracts for zero emission credits in an amount equal to approximately 16% of the actual amount of electricity delivered to retail customers during calendar year 2014, pursuant to Illinois’ zero emission standard. As a result of a 2018 IPA procurement event, which was approved by the ICC, Ameren Illinois entered into agreements to acquire zero emission credits through May 2027. Annual zero emission credit commitment amounts will be published by the IPA each May prior to the start of the subsequent planning year. Both renewable energy credits and zero emission credits have cost recovery mechanisms, which allow Ameren Illinois to ~~retail~~collect from, or refund to, customers ~~in Illinois during calendar year 2014. The zero-emission credit cost recovery mechanism, effective June 1, 2017, fully recovers or refunds, through customer rates,~~differences between actual costs incurred from the ~~variance in actual zero-emission credit costs incurred~~resulting contracts and the amounts collected from customers. ~~Ameren Illinois defers the variance as a regulatory asset or liability, respectively. These requirements were, and will continue to be, satisfied through ongoing IPA procurement events.~~

Ameren Missouri and Ameren Illinois have implemented energy-efficiency programs to educate their customers and to help ~~their customers~~them become more efficient ~~users~~energy consumers. These programs provide incentives to customers for installing newer, more efficient technology, and for using energy in a more conservation-minded manner. As a component of the energy-efficiency programs, Ameren Missouri and Ameren Illinois have invested in electric smart meters to provide customers more visibility to their energy consumption and facilitate more efficient use of energy. As of December 31, 2022, smart meters have been installed for 61% of Ameren Missouri’s electric customers. Ameren Illinois has completed its transition to smart meters, which have been installed for nearly all its electric and natural gas customers.

In Missouri, the ~~MEEIA~~Missouri Energy Efficiency Investment Act established a ~~regulatory framework~~rider that, among other things, allows electric utilities to

In ~~February 2016,~~2018, the MoPSC issued an order approving Ameren Missouri’s MEEIA ~~2016~~2019 plan. ~~That~~The plan ~~included~~includes a portfolio of customer energy-efficiency and demand response programs ~~along with a rider~~through December 2023. Ameren Missouri intends to ~~collect~~invest approximately $350 million over the ~~program costs,~~life of the ~~throughput disincentive, and~~plan, including $75 million in 2023. In addition, the plan includes a performance incentive ~~from customers.~~ that provides Ameren Missouri an opportunity to earn additional revenues by achieving certain customer energy-efficiency goals. If the target spending goals are achieved for 2023, additional revenues of $13 million would be recognized in 2023. Through 2022, Ameren Missouri has invested approximately $270 million in MEEIA 2019 customer energy-efficiency programs. Additionally, as part of its Smart Energy Plan, Ameren Missouri has invested $270 million in smart meters since 2019.

The ~~throughput disincentive recovery replaced~~MEEIA 2019 plan includes the ~~net shared benefits that were collected under~~continued use of the MEEIA ~~2013 plan.~~rider. The MEEIA rider allows Ameren Missouri to collect from, or refund to, customers any difference between actual program costs, lost electric margins, and any performance incentive and the ~~throughput disincentive~~amounts collected from customers, without a traditional regulatory rate ~~proceeding~~review, subject to MoPSC prudence reviews, until lower volumes resulting from the MEEIA programs are reflected in base rates. Customer rates, based upon both forecasted program costs and ~~throughput disincentive,~~lost electric margins and collected via the MEEIA rider, are reconciled annually to actual results.

State law requires Ameren Illinois to offer customer energy-efficiency programs, and imposes electric energy-efficiency savings goals and a maximum annual amount of investment in electric energy-efficiency programs, which is approximately $120 million annually through 2029 and may increase by up to approximately $30 million from 2026 to 2029 depending on the election of certain customers to participate in the programs. Every four years, Ameren Illinois is required to file a four-year electric energy-efficiency plan with the ICC. In ~~September 2017,~~June 2022, the ICC issued an order approving Ameren Illinois’ electric and natural gas energy-efficiency plans for 2022 through 2025, as well as ~~mechanisms by which program costs can be recovered from customers.~~regulatory recovery mechanisms. The order authorized electric and natural gas energy-efficiency program expenditures of ~~$394~~$476 million and ~~$62~~$66 million, respectively, ~~for~~over the ~~period 2018 through 2021. Additionally, as part of its IEIMA capital project investments, Ameren~~ four-year period.

Ameren Missouri and Ameren Illinois are responsible for the purchase and delivery of natural gas to their customers. Ameren Missouri and Ameren Illinois each develop and manage a portfolio of natural gas supply resources. These resources include firm natural gas supply ~~through~~ agreements with producers, firm interstate and intrastate ~~firm~~ transportation capacity, firm no-notice storage capacity leased from interstate pipelines, and on-system storage facilities to maintain natural gas deliveries to customers throughout the year and especially during peak demand periods. Ameren Missouri and Ameren Illinois primarily use Panhandle Eastern Pipe Line Company, Trunkline Gas Company, Natural Gas Pipeline Company of America, Mississippi River Transmission Corporation, Northern Border Pipeline Company, and Texas Eastern Transmission Corporation interstate pipeline systems to transport natural gas to their systems. In addition to transactions requiring physical delivery, certain financial instruments, including those entered into in the ~~NYMEX~~New York Mercantile Exchange futures market and in the ~~OTC~~over-the-counter financial markets, are used to hedge the price paid for natural gas. Natural gas ~~purchase~~supply costs are passed on to customers of Ameren Missouri and Ameren Illinois under PGA clauses, subject to prudence reviews by the MoPSC and the ICC. AsFor information regarding the percentage of ~~December 31, 2017,~~ Ameren ~~Missouri~~Missouri’s and Ameren ~~Illinois had price-hedged 66% and 75%, respectively, of their expected 2018~~Illinois’ projected remaining natural gas supply ~~requirements.~~requirements that are price-hedged through 2027, see Commodity Price Risk under Part II, Item 7A, of this report.

For additional information on our fuel, ~~and~~ purchased power, and natural gas for distribution supply, see Results of Operations and Liquidity and Capital Resources in Management’s Discussion and Analysis of Financial Condition and Results of Operations under Part II, Item 7, and Commodity Price Risk under Part II, Item 7A, of this report. Also see Note 1 – Summary of Significant Accounting Policies, Note 7 – Derivative Financial Instruments, Note 13 – Related-party Transactions, ~~and~~ Note 14 – Commitments and Contingencies, and Note 15 – Supplemental Information under Part II, Item 8, of this report.

Ameren’s chief executive officer and chief human resources officer, with the support of other leaders of the Ameren Companies, are responsible for developing and executing our workforce strategy. In addition to reviewing and determining the Ameren Companies’ compensation practices and policies for the chief executive officer and other executive officers, the Human Resources Committee of Ameren’s board of directors is responsible for oversight of Ameren’s human capital management practices and policies, including those related to diversity, equity, and inclusion. The Human Resources Committee and Ameren’s board of directors are updated regularly on human capital matters.

We strive to cultivate a values-based and continuous improvement culture that enables the sustainable execution of our core strategy and reflects the following characteristics:

We design our human capital management practices and policies to reinforce our core values, shape our culture, and drive employee engagement. In doing so, we strive to align our employees to our mission and vision, improve safety, enhance innovation, increase productivity, attract and retain top talent, and recognize employee contributions, among other things. We assess employee engagement through a variety of channels. As a part of our assessment, we conduct confidential employee engagement surveys at least annually to identify areas of strength and opportunities for improvement in our employees’ experience, and take actions aimed at increasing employee engagement. We also capitalized on opportunities presented by the COVID-19 pandemic and implemented work-from-home policies, advanced the digital enablement of our workforce, and enhanced our facilities and workforce policies and practices to increase collaboration and productivity.

As a part of our culture, every employee is expected to challenge any unsafe act, complete each workday safely, and provide feedback on safety and security matters. In addition to comprehensive safety and security standards, and mandatory health, safety, and security training programs for applicable employees, we promote programs designed to encourage employees to provide feedback on practices or actions that could harm employees, customers, or the Ameren Companies, including perceived issues related to safety, security (both physical and cyber), ethics and compliance violations, or acts of discrimination.

We seek to foster diversity, equity, and inclusion across our organization. We contribute to community-based organizations, hold diversity, equity, and inclusion leadership summits for employees and community leaders, and offer various training programs. We also offer a program to provide paid-time off for employees who engage in volunteer or learning opportunities with organizations that support diversity, equity, and inclusion. We also have employee resource groups, which bring together groups of employees who share common interests or backgrounds. Within these groups, employees collaborate to address concerns and provide training and development opportunities related to challenges or barriers, and offer support for each other, among other things.

Ameren’s leaders play a critical role in setting and executing Ameren’s strategic initiatives, modeling our values and culture, and engaging and enabling the workforce. As such, we seek to develop a strong, diverse leadership team. Management engages in an extensive succession planning process annually, which includes the involvement of Ameren’s board of directors. We develop our leaders both individually, through job rotations, work experiences, and leadership development programs, and as a team, through collaborative learning and mentoring relationships. Throughout the year, we offer a variety of forums intended to connect our leaders to our mission, values, strategy and culture, build leadership skills and capabilities, and to promote connection and inclusion. In addition, we evaluate our organizational structure and make adjustments and expand roles to facilitate execution of our strategy and organizational efficiency.

In order to attract and retain a skilled and diverse workforce, we promote an inclusive work environment, provide opportunities for employees to expand their knowledge and skill sets, and support career development. Our talent management initiatives include a wide range of recruiting partnerships and programs, including those programs discussed below. Our onboarding efforts are designed to ensure early engagement, including the opportunity to participate in mentoring programs. Additionally, employees are encouraged to participate in technical, professional, and leadership development opportunities, and outreach initiatives to engage with the communities that we serve, among other things. As our business needs change, we remain focused on ensuring that our workforce has the tools and skills necessary to deliver on our strategic initiatives.

We have established programs to recruit early and mid-career talent to further enhance the diversity of our workforce pipelines. These programs include skilled craft education and training for individuals interested in skilled craft roles, an intern/co-op program that serves as a pipeline for STEM-related careers, a career reentry program for experienced professionals transitioning from voluntary career breaks, a program for individuals transitioning from military service, and an early career rotation program. Additionally, each year management and the Human Resources Committee of Ameren’s board of directors review the diversity of our workforce, leadership team, and leadership development pipeline, as well as the actions taken to further enhance the diversity of our leadership team.

The majority of our workforce is comprised of skilled-craft and STEM-related professional and technical employees. Our workforce has been stable, with a total attrition rate of 8% in 2022. The majority of employee attrition is attributable to employee retirements, generally allowing for thoughtful workforce and succession planning in advance of these planned transitions. The following table presents our employee count and their average tenure at December 31, 2022, and the attrition rate in 2022:

Ameren’s workforce is diverse in many ways. At the officer level, which represents 48 individuals, 19% are female, and 21% are racially and/or ethnically diverse. The following table presents our total employee population that is represented by a collective bargaining unit, is a female, or is racially and/or ethnically diverse at December 31, 2022:

The following table presents Ameren’s employees by generation at December 31, 2022:

Collective bargaining units at Ameren’s subsidiaries consist of the International Brotherhood of Electrical Workers, the International Union of Operating Engineers, the Laborer’s International Union of North America, the United Association of Plumbers and Pipefitters, and the United Government Security Officers of America. The Ameren Companies expect continued constructive relationships with their respective labor unions. The Ameren Missouri collective bargaining unit contracts expire in 2025 and 2026, which cover 4% and 96% of represented employees, respectively. The Ameren Illinois collective bargaining unit contracts expire in 2023 and 2026, which cover 8% and 92% of represented employees, respectively.

The primary objective of our rewards program is to provide a total rewards package that attracts and retains a talented workforce and reinforces strong performance in a financially sustainable manner. Management continuously evaluates our core benefits in an effort to create a market-competitive, performance-based, shareholder-aligned total rewards package with a view towards balancing employee value and financial sustainability. We recognize that the rewards package required to attract and retain talent over the long term is about more than pay and benefits; it is about the total employee experience and support of their overall well-being. In addition to base salary, medical benefits, and retirement benefits, including pension for substantially all employees and 401(k) savings, our total rewards package includes short-term incentives and long-term stock-based compensation for certain employees. Further, we offer our employees various programs that encourage overall well-being, including wellness and employee assistance programs. We strive to provide a competitive and sustainable rewards package that supports our ability to attract, engage, and retain a talented and diverse workforce, while at the same time reinforcing and rewarding strong performance.

We are facing issues common to the electric and natural gas utility industry. These issues include:

We are monitoring all these issues. Except as otherwise noted in this report, we are unable to predict what impact, if any, these issues will have on our results of operations, financial position, or liquidity. For additional information, see Risk Factors under Part I, Item 1A, Outlook in Management’s Discussion and Analysis of Financial Condition and Results of Operations under Part II, Item 7, and Note 2 – Rate and Regulatory Matters, Note 9 – Callaway Energy Center, and Note 14 – Commitments and Contingencies under Part II, Item 8, of this report.

The Ameren Companies make available free of charge through Ameren’s website ~~(www.ameren.com)~~(www.amereninvestors.com) their annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, ~~eXtensible Business Reporting Language (XBRL) documents,~~ and any amendments to those reports filed with or furnished to the SEC pursuant to Sections 13(a) or 15(d) of the Exchange Act as soon as reasonably possible after such reports are electronically filed with, or furnished to, the SEC. These documents are also available through athe SEC’s website ~~maintained by the SEC~~ (www.sec.gov). Ameren’s ~~own~~ website is ~~our~~a channel of distribution for material information about the Ameren Companies. Financial and other material information is routinely posted to, and accessible at, Ameren’s website.

The Ameren Companies also make available free of charge through Ameren’s website the charters of Ameren’s board of directors’ ~~audit~~Audit and ~~risk committee, human resources committee, nominating~~Risk Committee, Human Resources Committee, Finance Committee, Nominating and ~~corporate governance committee, finance committee,~~Corporate Governance Committee, and ~~nuclear~~Nuclear, Operations and ~~operations committee;~~Environmental Sustainability Committee; the corporate governance guidelines; a policy regarding communications to the board of directors; a policy and procedures document with respect to related-person transactions; a code of ethics applicable to all directors, officers and employees; a supplemental code of ethics for principal executive and senior financial officers; ~~a code of business conduct applicable to all directors, officers and employees;~~ and a director nomination policy that applies to the Ameren Companies. The information on Ameren’s website, or any other website referenced in this report, is not incorporated by reference into this report.

Investors should review carefully the following material risk factors and the other information contained in this report. The risks that the Ameren Companies face are not limited to those in this section. There may be further risks and uncertainties that are not presently known or that are not currently believed to be material that may adversely affect the results of operations, financial position, and liquidity of the Ameren Companies.

We are subject to federal, state, and local regulation. ~~This~~The extensive regulatory ~~framework,~~frameworks, some of which isare more specifically identified in the following risk factors, ~~regulates,~~regulate, among other matters, the electric and natural gas utility industries; the rate and cost structure of ~~utilities;~~utilities, including an allowed ROE; the operation of nuclear power plants; the construction and operation of generation, transmission, and distribution facilities; the acquisition, disposal, depreciation and amortization of assets and facilities; the electric transmission system reliability; and wholesale and retail competition. In the planning and management of our operations, we must address the effects of existing and proposed laws and regulations and potential changes in ~~the~~our regulatory ~~framework,~~frameworks, including initiatives by federal and state legislatures, RTOs, utility regulators, and taxing ~~authorities.~~authorities, and actions by local jurisdictions that may affect the constructing or siting of facilities. Significant changes in the nature of the regulation of our businesses, including expiration or discontinuation of, or significant changes to, existing regulatory mechanisms, could require changes to our business planning and management of our businesses and could adversely affect our results of operations, financial position, and liquidity. Failure to obtain adequate rates or regulatory approvals in a timely manner; failure to obtain necessary licenses or permits from regulatory authorities; the impact of new or modified laws, regulations, standards, interpretations, or other legal requirements; or increased compliance costs could adversely affect our results of operations, financial position, and liquidity.

The rates that we are allowed to charge for our utility services significantly influence our results of operations, financial position, and liquidity. The electric and natural gas utility industry is highly regulated. The utility rates charged to customers are determined by governmental entities, including the MoPSC, the ICC, and the FERC. Decisions by these entities are influenced by many factors, including the cost of providing service, the prudency of expenditures, the quality of service, regulatory staff knowledge and experience, customer intervention, and economic conditions, as well as social and political views. Decisions made by these governmental entities regarding customer rates are largely outside of our control. We are exposed to regulatory lag, including the impact of inflationary pressures, and cost disallowances to varying degrees by jurisdiction, which, if unmitigated, could adversely affect our results of operations, financial position, and liquidity. Rate orders are also subject to appeal, which creates additional uncertainty as to the rates that we will ultimately be allowed to charge for our services. From time to time, our regulators may approve trackers, riders, or other recovery mechanisms that allow electric or natural gas rates to be adjusted without a traditional regulatory rate ~~proceeding.~~review. These mechanisms could be changed or terminated.

Ameren Missouri’s electric and natural gas utility rates and Ameren Illinois’ natural gas utility rates are typically established in regulatory proceedings that take up to 11 months to complete. Ameren Missouri’s electric and natural gas utility rates established in those proceedings are primarily based on

Rates include an allowed ~~rate of~~ return on investments established by the regulator, including a return at the applicable WACC on ~~invested capital, both debt and equity,~~rate base, and an amount for income taxes based on the currently applicable statutory income tax rates and amortization associated with excess deferred income taxes. Although rate regulation is premised on providing an opportunity to earn a reasonable rate of return on ~~invested capital,~~rate base, there can be no assurance that the regulator will determine that our costs were prudently incurred or that the regulatory process will result in rates that will produce full recovery of such costs or provide for an opportunity to earn a reasonable return on those investments.

Ameren Illinois ~~participates in a~~is utilizing the IEIMA performance-based formula ratemaking framework ~~established pursuant~~to establish annual customer rates effective through 2023 and will reconcile the related revenue requirements through an IEIMA reconciliation. The IETL resulted in changes to the ~~IEIMA for its~~regulatory framework applicable to Ameren Illinois’ electric distribution ~~service. Beginning~~business by giving Ameren Illinois the option to file an MYRP with the ICC by mid-January 2023, with rates effective beginning in ~~2017,~~2024, or establish future rates through a traditional regulatory rate review, among other things. An MYRP would establish rates for a four-year period, and Ameren Illinois has the ~~FEJA allowed~~option to file for an MYRP every four years. Ameren Illinois elected to file an MYRP in January 2023 for rates effective in 2024 through 2027 with the ICC. The MYRP also allows Ameren Illinois to ~~recover~~reconcile its actual revenue requirement, as adjusted for certain cost variations, to ICC-approved electric distribution service rates on an annual basis, subject to a reconciliation cap. The reconciliation cap limits the annual adjustment to 105% of the annual revenue requirement approved by the ICC. Certain variations from forecasted costs would be excluded from the reconciliation cap, including those associated with major storms; new business and facility relocations; changes in the timing of certain expenditures or investments into or out of the applicable calendar year; and changes in interest rates, income taxes, taxes other than income taxes, pension and other post-retirement benefits costs, and amortization of certain assets. The reconciliation cap also excludes costs recovered through riders outside of base rates, such as riders for electric energy-efficiency investments, power procurement and transmission services, renewable energy credit compliance, zero emission credits, certain environmental costs, and bad debt write-offs, among others. Ameren Illinois’ existing riders will remain effective and electric distribution service revenues will continue to be decoupled from sales volumes under the MYRP. The actual revenue requirement for a ~~given~~particular year ~~independent~~would incorporate Ameren Illinois’ year-end rate base and actual capital structure for such year, provided that the common equity ratio in such capital structure may not exceed that approved by the ICC in the MYRP. In addition, the ICC will determine the ROE applicable to each year of ~~actual~~the four-year period. Changes in economic conditions could result in the predetermined ROE becoming inadequate over the four-year period. By law, Ameren Illinois’ electric distribution revenues are decoupled from sales volumes regardless of the process used to establish electric distribution rates, which ensures that the electric distribution revenues authorized in a regulatory rate review are not affected by changes in sales volumes. ~~Since June 2017, the FEJA has also allowed~~ Ameren ~~Illinois to earn a return on its~~Illinois’ electric energy-efficiency program rider, which includes a return at the applicable WACC on its program investments, ~~which~~ is subject to performance-based formula ratemaking. The ICC annually reviews each Ameren ~~Illinois’~~Illinois rate ~~filings~~filing for reasonableness and prudency. If the ICC were to conclude that Ameren Illinois’ costs were not prudently incurred, the ICC would disallow recovery of such costs.

The ~~return on equity component~~allowed ROE under the IEIMA and electric energy-efficiency formula ratemaking recovery mechanisms is based on the ~~FEJA is equal to the calendar year~~annual average of the monthly yields of the 30-year United States Treasury bonds plus 580 basis points. Therefore, Ameren Illinois’ annual ~~return on equity under the formula ratemaking frameworks~~ROE for ~~both~~ its electric distribution ~~service and its electric energy-efficiency investments~~business is directly correlated to the yields on such bonds, which are outside of Ameren Illinois’ control. ~~With respect to electric distribution service, a~~A 50 basis point change in the annual average of the monthly yields of the 30-year United States Treasury bonds would result in an estimated $8$12 million change in Ameren’s and Ameren Illinois’ annual net income, based on ~~its 2018~~Ameren Illinois’ 2023 projected year-end rate ~~base.~~base, including electric energy-efficiency investments.

Ameren ~~Illinois~~Illinois’ electric distribution business is also subject to performance standards. Failure to achieve the standards would result in a reduction in the company’s allowed ~~return on equity~~ROE calculated under the formula ratemaking ~~formulas.~~recovery mechanisms. The performance standards applicable to electric distribution service under the IEIMA include improvements in service reliability to reduce both the frequency and duration of outages, a reduction in the number of estimated bills, a reduction of consumption from inactive meters, and a reduction in bad

The QIP provides Ameren Illinois with recovery of, and a return on, qualifying natural gas infrastructure investments that are placed in service between regulatory rate reviews. Infrastructure investments under the QIP earn a return at the applicable WACC. Ameren Illinois’ QIP is subject to a rate impact limitation of a cumulative 4% per year since the most recent delivery service rate order, with no single year exceeding 5.5%. If the rate impact limitation was met in a particular year, the amount of rate base causing the QIP rate to exceed the limitation would be exposed to regulatory lag until a year when that amount could be recovered under QIP or is added to rate base as a part of a regulatory rate review. Upon issuance of a natural gas delivery service rate order, QIP rate base is transferred to base rates and the QIP is reset to zero. Without legislative action, the QIP will expire after December 2023. If Ameren Illinois is unable to recover investments under the QIP or there is no other regulatory change, Ameren Illinois will be subject to increased regulatory lag on its natural gas infrastructure investments that are placed in service between regulatory rate reviews, which could adversely affect Ameren’s and Ameren Illinois’ investment plans and results of operations, financial position, and liquidity.

Missouri Senate Bill 745 became effective on August 28, 2022. The law extended Ameren Missouri’s PISA election through December 2028 and allows for an additional extension through December 2033 if requested by Ameren Missouri and approved by the ~~savings goals~~MoPSC, among other things. The law established a 2.5% annual limit on increases to the electric service revenue requirement used to set customer rates due to the inclusion of incremental PISA deferrals in the revenue requirement. The limitation will be effective for revenue requirements approved

Our electric generation, transmission, and distribution and natural gas distribution and storage operations must comply with a variety of ~~which could adversely affect our results of operations, financial position, and liquidity.~~

We are also subject to liability under environmental laws that address the remediation of environmental contamination on property currently or formerly owned by us or by our predecessors, as well as property contaminated by hazardous substances that we generated. Such properties include MGP sites, substations, and third-party sites, such as landfills. Additionally, private individuals may seek to enforce environmental laws ~~and regulations~~ against us. They could allege injury from exposure to hazardous materials, allege a failure to comply with environmental laws, ~~and regulations,~~ seek to compel remediation of environmental contamination, or seek to recover damages resulting from that contamination.

Ameren is also subject to risks from changing or conflicting interpretations of existing laws and regulations. The EPA is engaged in an enforcement initiative to determine whether coal-fired power plants failed to comply with the requirements of the NSR and NSPS provisions under the Clean Air Act when the power plants implemented modifications. In January 2011, the United States Department of Justice, on behalf of the EPA, filed a complaint against Ameren Missouri in the United States District Court for the Eastern District of ~~Missouri. The complaint, as amended in October 2013, alleged~~Missouri alleging that ~~in performing~~ projects ~~at its Rush Island coal-fired energy center~~performed in 2007 and 2010 ~~Ameren Missouri~~at the coal-fired Rush Island Energy Center violated provisions of the Clean Air Act and Missouri law. ~~The litigation has been divided into two phases: liability and remedy.~~ In January 2017, the district court issued a liability ruling ~~that~~against Ameren Missouri and, in September 2019, entered a remedy order. That remedy order included a requirement to install a flue gas desulfurization system at the ~~projects violated provisions~~Rush Island Energy Center, which was upheld through an appeals process by the United States Court of Appeals for the Eighth Circuit in the fourth quarter of 2021. Based on its assessment of available legal, operational and regulatory alternatives, Ameren Missouri filed a motion in December 2021 with the district court to modify the remedy order to allow the retirement of the ~~Clean Air Act~~Rush Island Energy Center in advance of its previously expected useful life in lieu of installing a flue gas desulfurization system. The March 31, 2024 compliance date contained in the district court’s September 2019 remedy order remains in effect unless extended by the district court. In July 2022, in response to an Ameren Missouri request for a final, binding reliability assessment, the MISO designated the Rush Island Energy Center as a system support resource and concluded that certain mitigation measures, including transmission upgrades, should occur before the energy center is retired. The transmission upgrade projects have been approved by the MISO, and design and procurement activities necessary to complete the upgrades are underway. Ameren Missouri ~~law.~~expects to complete the upgrades by mid-2025. In October 2022, the FERC approved a system support resource agreement, which became effective retroactively as of September 1, 2022. The ~~case then proceeded~~agreement details the manner of continued operation for a system support resource that results in operating during peak demand times and emergencies. The system support resource designation and the related agreement are subject to annual renewal and revision. In September 2022, the Rush Island Energy Center began operating consistent with the system support resource agreement. In addition, in October 2022, the FERC established hearing and settlement procedures in response to an August 2022 request from Ameren Missouri for recovery of non-energy costs under the related MISO tariff. The FERC is under no deadline to issue an order related to this proceeding. Revenues and costs under the MISO tariff are expected to be included in the FAC. The district court has the authority to determine the

Ameren and Ameren Missouri have incurred, and expect to incur, significant costs with respect to environmental compliance and site remediation. New or revised environmental regulations, enforcement initiatives, or legislation could result in a significant increase in capital expenditures and operating costs, decreased revenues, ~~increased financing requirements,~~ penalties or fines, or reduced operations or closure of some of Ameren Missouri’s ~~coal-fired~~coal-and natural gas-fired energy centers, which, in turn, could lead to increased liquidity and financing needs, and higher financing costs. Actions required to ensure that Ameren Missouri’s facilities and operations are in compliance with environmental laws ~~and regulations~~ could be

There is increasing concern and activism among various external stakeholders, both nationally and internationally, about climate change, including public concerns about the potential environmental impacts from the combustion of fossil fuels, as well as pressure from public interest groups regarding limiting the use of natural gas. Federal, state, and local authorities, including the United States Congress, have considered initiatives to further restrict greenhouse gases to address global climate change. Additionally, international agreements could lead to future federal or state legislation or regulations. In 2015, the United Nations Framework Convention on Climate Change reached consensus among approximately 190 nations on an agreement, known as the Paris Agreement, that establishes a framework for greenhouse gas mitigation actions by all countries, with a goal of holding the increase in global average temperature to below 2 degrees Celsius above pre-industrial levels and an aspiration to limit the increase to 1.5 degrees Celsius. The ~~TCJA is complex and significantly affects~~Biden administration has a policy commitment regarding a reduction in greenhouse gas emissions for the ~~Ameren Companies.~~ United States, but rulemaking to achieve such reductions has not yet been implemented. Actions taken to implement the Paris Agreement could result in future additional greenhouse gas reduction requirements in the

The TCJA, among other things, reduced the federal statutory corporate income tax rate from 35% to 21%, effective January 1, 2018. Additionally, the TCJA eliminated 50% accelerated depreciation tax benefits for nearly all regulated utility capital investments made after September 27, 2017. As of December 31, 2017, Ameren ~~recorded a noncash charge to earnings of $154 million~~is targeting net-zero carbon emissions by 2045, as well as a result of the revaluation of deferred taxes, largely attributable to Ameren (parent). Ameren also reclassified deferred income tax liabilities of $2.4 billion to regulatory liabilities. This reclassification is due to the60% reduction ~~of the federal statutory corporate income tax rate, which reduced such income tax obligations,~~by 2030 and ~~the expected return of funds previously collected from customers. Our rate-regulated businesses recover income taxes in customer rates~~an 85% reduction by 2040 based on ~~the federal~~2005 levels. Ameren’s goals include both direct emissions from operations, as well as electricity usage at Ameren buildings, including other greenhouse gas emissions of methane, nitrous oxide, and ~~state statutory corporate income tax rates in effect when the revenue requirements used to determine those rates were established. However, there~~sulfur hexafluoride. Achievement of these goals is a timing difference between when we collect funds from our customers for income taxes and when we pay such taxes. Excess deferred taxes were created as the deferred income tax obligation decreased due to a reduction in the federal statutory corporate income tax rate.

~~The~~We are subject to FERC ~~can impose civil penalties of approximately $1.2 million per violation per day for violation of its~~ regulations, rules, and orders, including ~~mandatory NERC reliability standards.~~standards required by the NERC. As owners and operators of bulk power transmission systems and electric energy centers, we are subject to mandatory NERC reliability standards, including cybersecurity standards. In addition, our natural gas transmission, distribution, and storage facilities systems are subject to PHMSA rules and regulations. Compliance with these ~~mandatory~~ reliability standards, rules, and regulations may subject us to higher operating costs and may result in increased capital expenditures. We may also incur higher operating costs to comply with potential new regulations issued by these regulatory bodies. If we were found not to be in compliance with these mandatory NERC reliability standards, PHMSA rules and regulations, or FERC regulations, rules, and orders, we could incur substantial monetary penalties and other sanctions, which could adversely affect our results of operations, financial position, and liquidity. The FERC can impose civil penalties of approximately $1.5 million per violation per day for violation of its regulations, rules, and orders, including mandatory NERC reliability standards. The FERC also conducts audits and reviews of Ameren Missouri’s, Ameren Illinois’, and ATXI’s accounting records to assess the accuracy of ~~its~~their respective formula ratemaking process, and it can require refunds to customers for previously billed amounts, with interest.

Additionally, pursuant to the IETL, Illinois utilities are subject to new requirements and provisions related to ethical conduct and transparency, including submitting an annual ethics and compliance report to the ICC. The law authorizes the ICC to initiate an investigation into how customer funds were used if ethical misconduct is determined to have occurred at an Illinois utility, potentially requiring the utility to issue refunds and imposing a potential penalty of up to $0.5 million per violation.

We expect to ~~incur~~make significant capital expenditures to maintain and improve our electric and natural gas utility infrastructure and to comply with existing environmental regulations. We estimate that we will invest up to ~~$11.4~~$20.5 billion (Ameren Missouri – up to ~~$4.5~~$10.8 billion; Ameren Illinois – up to ~~$6.6~~$9.5 billion; ATXI – up to ~~$0.3~~$0.2 billion) of capital expenditures from ~~2018~~2023 through ~~2022. These~~2027. For additional information on these estimates, ~~do not reflect the potential additional investments identified~~see Liquidity and Capital Resources – Capital Expenditures in ~~Ameren Missouri’s integrated resource plan, which could represent incremental investments~~Management’s Discussion and Analysis of ~~approximately $1 billion through 2020~~Financial Condition and are subject to regulatory approval. They also do not reflect potential additional investments that Ameren Missouri could make if improvements in its regulatory frameworks were made. These estimates include allowance for equity funds used during construction.Results of Operations under Part II, Item 7, of this report. Investments in Ameren’s rate-regulated operations are expected to be recoverable from customers, but they are subject to prudence reviews and are exposed to regulatory lag of varying degrees by jurisdiction.

Any of these ~~projects. There is a risk that an energy center might not be permitted~~risks could result in higher costs, the inability to ~~continue to operate if pollution control equipment is not installed by prescribed deadlines~~complete anticipated projects, or ~~does not perform as expected. Should any such pollution control equipment not be installed on time or not perform as expected, Ameren Missouri could be subject to additional costs~~facility closures, and ~~to the loss of its investment in the project or facility. All of these project and construction risks~~ could adversely affect our results of operations, financial position, and liquidity.

Our financial performance depends on the successful operation of electric generation, transmission, and distribution facilities. Operation of electric generation, transmission, and distribution facilities involves many risks, including:

The foregoing risks could affect the controls and operations of our facilities or impede our ability to meet regulatory requirements, which could increase operating costs, increase our capital requirements and costs, reduce our revenues, or have an adverse effect on our liquidity.

Ameren Missouri owns and operates coal-fired energy centers. About 97% of Ameren Missouri’s coal is purchased from the Powder River Basin in Wyoming, which has a limited number of suppliers. Deliveries from the Powder River Basin have occasionally been restricted because of rail congestion, staffing and equipment issues, infrastructure maintenance, derailments, weather, and supplier financial hardship. Coal suppliers in the Powder River Basin are experiencing financial hardship because of a decrease in demand resulting from increased natural gas use and renewable energy generation, and the impact of environmental regulations and concerns related to coal-fired generation. These financial hardships have resulted in bankruptcy filings by certain coal suppliers in recent years. As of December 31, 2022, coal inventories at the Labadie and Sioux energy centers were below targeted levels due to transportation delays in 2022. Additional delays or disruptions in the delivery of coal, failure of our coal suppliers to provide adequate quantities or quality of coal, or lack of adequate inventories of coal, including low-sulfur coal used to comply with environmental regulations, could have adverse effects on Ameren Missouri’s electric generation operations. If Ameren Missouri is unable to obtain an adequate supply of coal under existing agreements, it may be required to purchase coal at higher prices or be forced to reduce generation at its coal-fired energy centers, which could adversely affect Ameren’s and Ameren Missouri’s results of operations, financial position, and liquidity.

Ameren Missouri’s ownership of the Callaway ~~energy center~~Energy Center subjects it to risks associated with nuclear generation, including:

The NRC has broad authority under federal law to impose licensing and safety requirements for nuclear facilities. In the event of noncompliance, the NRC has the authority to impose fines or to shut down a unit, or both, depending upon its assessment of the severity of the situation, until compliance is achieved. Revised safety requirements promulgated from time to time by the NRC could necessitate substantial capital expenditures at the Callaway ~~energy center.~~Energy Center. In addition, if a serious nuclear incident were to occur, it could adversely affect Ameren’s and Ameren Missouri’s results of operations, financial condition, and liquidity. A major incident at a nuclear facility anywhere in the world could cause the NRC to limit or prohibit the operation of any domestic nuclear unit and could also cause the NRC to impose additional conditions or requirements on the industry, which could increase costs and result in additional capital expenditures. While the Callaway Energy Center is in compliance with the current NRC standards relating to seismic design and risk, these standards also require Ameren Missouri to ~~further evaluate~~address periodic changes to seismic hazard data and evaluation methods for the impact of an earthquake on its Callaway ~~energy center~~Energy Center due to its proximity to a fault line, which could require ~~the~~seismic risk evaluation updates and installation of additional capital equipment.

Inherent in our natural gas distribution businesses, which includes transmission, distribution, and storage ~~activities~~facilities, are a variety of hazards and operating risks, such as leaks, explosions, mechanical problems and cybersecurity risks, which could cause substantial financial ~~losses.~~losses, including fines and penalties. In addition, these hazards could result in serious injury, loss of human life, significant damage to property, environmental impacts, and impairment of our operations, which in turn could lead us to incur substantial losses. The location of

Our aging infrastructure may pose risks to system reliability and expose us to expedited or unplanned significant capital expenditures and operating costs. All of Ameren Missouri’s coal-fired energy centers were constructed prior to 1978, and the Callaway ~~energy center~~Energy Center began operating in 1984. The age of these energy centers increases the risks of unplanned outages, reduced generation output, and higher maintenance expense. ~~If, at the end of its life, an energy center’s cost has not been fully recovered,~~Further, Ameren Missouri ~~may~~would be adversely affected if the MoPSC does not allow ~~such cost to be recovered in rates. Ameren Missouri may also be adversely affected if~~recovery of the ~~MoPSC does not allow full or timely recovery of~~remaining investment and decommissioning costs associated with the retirement of an energy ~~center.~~center, as well as the ability to earn a return on that remaining investment and those decommissioning costs. In addition, as discussed above, Ameren Missouri expects the retirement date of its Rush Island Energy Center to be accelerated from the date reflected in depreciation rates approved in the December 2021 MoPSC electric rate order. Aging transmission and distribution facilities are more prone to failure than new facilities, which results in higher maintenance expense and the need to replace these facilities with new infrastructure. Even ifwhen the system is properly maintained, its reliability may ultimately deteriorate and negatively affect our ability to serve our customers, which could result in increased costs associated with regulatory oversight. The frequency and duration of customer outages are among the IEIMA and IETL performance standards. Any failure to achieve these standards will result in a reduction in Ameren Illinois’ allowed ~~return on equity~~ROE on electric distribution assets. The higher maintenance costs associated with aging infrastructure and capital expenditures for new or replacement infrastructure, compounded by increasing interest rates and inflationary pressures, could cause additional rate volatility for our customers, resistance by our regulators to allow customer rate increases, and/or regulatory lag in some of our jurisdictions, any of which could adversely affect our results of operations, financial position, and liquidity.

Without a regulatory mechanism to ensure recovery, declines in energy usage ~~will~~could result in an under-recovery of ~~Ameren Missouri’s~~our revenue ~~requirement. Such declines could occur due to a number of factors:~~

Decreased use of our generation, transmission, and distribution services might result in stranded costs, which ultimately might not be recovered through rates, and therefore could lead to an impairment or abandonment of assets.

Ameren is a holding company; therefore, its primary assets are its investments in the common stock of its subsidiaries, including Ameren Missouri, Ameren Illinois, and ATXI. As a result, Ameren’s ability to pay dividends on its common stock depends on the earnings of its subsidiaries and the ability of its subsidiaries to pay dividends or otherwise transfer funds to Ameren. Similarly, Ameren’s ability to service its debt obligations is dependent upon the earnings of its operating subsidiaries and the distribution of those earnings and other payments, including payments of principal and interest under affiliate indebtedness. The payment of dividends to Ameren by its subsidiaries in turn depends on their results of operations, and other items affecting retained earnings, and available cash. Ameren’s subsidiaries are separate and distinct legal entities and have no obligation, contingent or otherwise, to pay any dividends or make any other distributions (except for payments required pursuant to the terms of affiliate borrowing arrangements and cash payments under the tax allocation agreement) to Ameren. Under the IRA, a 15% minimum tax on adjusted financial statement income, as defined in the law, is assessed against corporations whose average annual adjusted financial statement income exceeds $1 billion for three consecutive preceding tax years, effective for tax

A part of our core strategy focuses on disciplined cost management, including prudently monitoring all of our expenses. However, we have observed inflationary pressures related to prices of commodities, labor, services, materials and supplies, and other costs. We are uncertain whether these inflationary pressures will continue and at what rate. These inflationary pressures, as well as increasing interest rates, could impact our ability to control costs, to make substantial investments in our businesses, to recover costs and investments, to earn our allowed ROEs within frameworks established by our regulators, and/or to maintain affordability of our services for our customers. In addition, these inflationary pressures and increasing interest rates could adversely affect our customers’ usage of, or payment for, our services. Additionally, volatility in the commodities market could increase collateral postings and prepayments. Also, market volatility could significantly affect the investment performance of Ameren’s COLI. Significant increases in our costs could increase our financing needs and otherwise adversely affect our results of operations, financial position, and liquidity. For additional information on purchased power costs, see Outlook under Part II, Item 7, of this report.

Related to benefits, Ameren ~~offers defined benefit pension and postretirement benefit plans covering substantially all of its union employees. Ameren offers~~has defined benefit pension plans covering substantially all of its ~~non-union~~ employees and has postretirement benefit plans covering non-union employees hired before October ~~2015.~~2015 and union employees hired before January 2020. Assumptions related to future costs, returns on investments, interest rates, timing of employee retirements, and mortality, as well as other actuarial matters, have a significant impact on our customers’ rates and our plan funding requirements. Ameren’s total ~~unfunded obligation under its~~ pension and postretirement benefit plans ~~was $551~~were overfunded by $377 million as of December 31, ~~2017.~~2022. Ameren expects to fund its pension plans at a level equal to the greater of the pension cost or the legally required minimum contribution. Based on ~~Ameren’s~~its assumptions at December 31, ~~2017,~~2022, its investment performance in ~~2017,~~2022, and its pension funding policy, Ameren does not expect to make material contributions in 2023 through 2025, and expects to make ~~annual~~aggregate contributions of ~~less than $1 million to $60~~$170 million in ~~each of the next five years, with aggregate estimated contributions of $120 million. We expect~~2026 and 2027. Ameren ~~Missouri’s~~Missouri and Ameren ~~Illinois’ portions~~Illinois estimate that their portion of the future funding requirements towill be ~~35%~~40% and ~~55%~~50%, respectively. These ~~amounts are estimates. They~~estimated contributions may change ~~with~~based on actual investment performance, changes in interest rates, changes in our assumptions, changes in government regulations, and any voluntary contributions.

Our results are influenced by the expectations of our customers, investors, legislators, regulators, and creditors. Those expectations are based, in part, on the reliability and affordability of our utility services. Service interruptions and facility shutdowns can occur due to failures of equipment as a result of severe or destructive weather or other causes. The ability of Ameren Missouri and Ameren Illinois to respond promptly to such failures can affect customer satisfaction. In addition to system reliability issues, the success of modernization efforts, our ability to safeguard sensitive customer information and protect our systems from cyber attacks, and other actions can affect customer satisfaction. The level of rates, the timing and magnitude of rate increases, and the volatility of rates can also affect regulator and customer satisfaction.

Our ability to successfully execute our strategic plan, including the transition of Ameren Missouri’s generation fleet and achievement of the carbon emission reduction targets outlined in the 2022 Change to the 2020 IRP, may affect customers’, investors’, legislators’, regulators’, and creditors’ opinions and actions. Additionally, negative perceptions or publicity resulting from increasing ~~costs~~scrutiny of ESG practices could negatively impact our reputation, investment in our common stock, or our access to capital markets. Customers’, investors’, legislators’, regulators’, and ~~funding requirements~~creditors’ opinions of us can also be affected by media coverage, including social media, which may include information, whether factual or not, that damages our brand and reputation.

If customers, investors, legislators, regulators, or creditors have or develop a negative opinion of us and our utility services, this could result in increased costs associated with regulatory oversight and could affect the ROEs we are allowed to earn, as well as the access to, and

Our businesses depend upon our ability to employ and retain key officers and other skilled professional and technical employees. Certain specialized knowledge that focuses on skilled-craft and STEM-related disciplines is required to construct and operate generation, transmission, and distribution assets. Further, a significant portion of our work force is nearing retirement. As of December 31, 2022, approximately 25%, 25%, and 23% of Ameren’s, Ameren Missouri’s, and Ameren Illinois’ total employees were 55 years old or older, respectively. We are also party to collective bargaining agreements that collectively represent about 47%, 59%, and 55% of Ameren’s, Ameren Missouri’s and Ameren Illinois’ total employees, respectively. The Ameren Missouri collective bargaining unit contracts expire in 2025 and 2026, which cover 4% and 96% of represented employees, respectively. The Ameren Illinois collective bargaining unit contracts expire in 2023 and 2026, which cover 8% and 92% of represented employees, respectively. Remote working arrangements could increase our data security risks, including loss of data related to sensitive customer, employee, financial, and operating system information, through insider or outsider actions. Certain events, such as significant delays in finding appropriate replacement talent, inadequately trained replacement employees, a mismatch of skill sets to future needs, any work stoppage experienced in connection with negotiations of collective bargaining agreements, or challenges with remote working arrangements, could adversely affect our operations.

Like other electric and natural gas utilities, our energy centers, fuel storage facilities, transmission and distribution facilities, and enterprise information systems may be affected by malicious acts, terrorist activities and other intentionally disruptive acts, including physical and cyber attacks, which could disrupt our ability to produce or distribute our energy products. In the industry, there continues to be attacks on energy infrastructure, such as substations and related assets. The threat landscape continues to expand, which may result in more attacks in the future. Any such incident could limit our ability to generate, purchase, or transmit power or natural gas and could have significant regional economic consequences. Any such disruption could result in a significant decrease in revenues, a significant increase in costs including those for repair, or adversely affect economic activity in our service territory which, in turn, could adversely affect our results of operations, financial position, and liquidity.

There has been an increase in the number and sophistication of physical and cyber attacks across all industries worldwide. Physical attacks could include sabotaging, vandalizing, or burglarizing transmission and distribution facilities, which are unmanned, widely dispersed, and often in isolated areas, or the theft of physical data and information. Cyber attacks could include viruses, malicious or destructive code, phishing attacks, denial of service attacks, supply chain attacks, ransomware and other extortion-based attacks, improper access by third parties, attacks on email systems, and attacks leading to data loss, operational control, or exploitation of vulnerabilities specific to internally developed systems or to those provided and/or maintained by our suppliers, among various other security breaches. A security breach of our physical assets or in our information systems could affect the reliability of the transmission and distribution system, disrupt electric generation, including nuclear generation, and/or subject us to financial harm resulting from theft or the inappropriate release or destruction of certain types of information, including sensitive customer, employee, financial, and operating system information. Many of our suppliers, vendors, contractors, and information technology providers have access to systems that support our operations and maintain customer and employee data. A breach of these third-party systems could adversely affect our business as if it was a breach of our own system. If a significant breach occurred, our reputation could be adversely affected, customer confidence could be diminished, availability of our services could be impacted, and/or we could be subject to increased costs associated with regulatory oversight, fines or legal claims, any of which could result in a significant decrease in revenues or significant costs for remedying the impacts of such a breach. Our generation, transmission, and distribution systems are part of an interconnected grid. Therefore, a disruption caused by a physical or cyber incident at another utility, electric generator, RTO, or commodity supplier could also adversely affect our businesses. Insurance might not be adequate to cover losses that arise in connection with these events. In addition, new regulations could require changes in our security measures and result in increased costs. The occurrence of any of these events could adversely affect our results of operations, financial position, and liquidity.

We rely on the issuance of short-term and long-term debt and equity as significant sources of liquidity and funding for capital requirements not satisfied by our operating cash flow, as well as to refinance existing long-term debt. The inability to raise debt or equity capital on reasonable terms, or at all, could negatively affect our ability to maintain or to expand our businesses. General economic factors beyond our control might create uncertainty that could increase our cost of capital or impair or eliminate our ability to access the debt, equity, or credit markets, including our ability to draw on bank credit facilities. These factors include depressed economic conditions, a recession,

None.

For information on our principal properties, see the energy center ~~table~~and in-service utility-related properties tables below. See also Liquidity and Capital Resources and Regulatory Matters in Management’s Discussion and Analysis of Financial Condition and Results of Operations under Part II, Item 7, of this report for a discussion of planned ~~additions, replacements or transfers.~~additions. See also Note 5 – Long-term Debt and Equity Financings and Note 14 – Commitments and Contingencies under Part II, Item 8, of this report.

The following table shows the anticipated capability of ~~Ameren Missouri’s~~our energy centers at the time of ~~Ameren Missouri’s~~the expected ~~2018~~2023 peak summer electrical ~~demand:~~

The following table presents in-service electric and natural gas utility-related properties for Ameren Missouri and Ameren Illinois as of December 31, ~~2017:~~2022:

Our other properties include office buildings, warehouses, garages, and repair shops.

With only a few exceptions, we have fee title to all principal energy centers and other units of property material to the operation of our businesses, and to the real property on which such facilities are located (subject to mortgage liens securing our outstanding first mortgage bonds and to certain permitted liens and judgment liens). The exceptions as of January 31, 2023 are as follows:

Substantially all of the properties and plant of Ameren Missouri and Ameren Illinois are subject to the liens of the indentures securing their respective mortgage bonds.

Ameren Missouri ~~has~~ conveyed most of its Peno Creek CT ~~energy center~~Energy Center to the city of Bowling Green, Missouri through December 2022. Ameren Missouri had rights and ~~leased~~obligations as the operator of the energy center ~~back from~~under a long-term agreement with the city ~~through 2022.~~of Bowling Green. Under the terms of this ~~capital lease,~~agreement, Ameren Missouri iswas responsible for all operation and maintenance ~~for~~at the energy center. Ownership of the energy center ~~will transfer~~transferred to Ameren Missouri ~~at the expiration of the lease,~~in December 2022, at which time the property, plant, and equipment ~~will become~~became subject to the lien of ~~any~~the Ameren Missouri ~~first~~ mortgage bond ~~indenture then in effect.~~indenture.

Ameren Missouri operates a CT energy center located in Audrain County, Missouri. Ameren Missouri ~~has~~had rights and obligations as ~~lessee~~the operator of the CT energy center under a long-term ~~lease~~agreement with Audrain County. ~~The lease will expire in December 2023.~~ Under the terms of this ~~capital lease,~~agreement, Ameren Missouri iswas responsible for all operation and maintenance ~~for~~at the energy center. While the agreement was scheduled to expire in December 2023, Ameren Missouri and Audrain County mutually agreed to terminate the agreement in January 2023. Ownership of the energy center ~~will transfer~~was transferred to Ameren Missouri ~~at the expiration of the lease,~~in January 2023, at which time the property, plant, and equipment ~~will become~~became subject to the lien of ~~any~~the Ameren Missouri ~~first~~ mortgage bond ~~indenture then in effect.~~indenture. See Note 5 – Long-term Debt and Equity Financings under Part II, Item 8, of this report for additional information for both agreements associated with the Peno Creek CT and Audrain County CT energy centers.

Ameren management cautions that the stock price performance shown above should not be considered indicative of future stock price performance.

Below is a summary description of Ameren’s principal subsidiaries ~~including~~– Ameren Missouri, Ameren Illinois, and ATXI. Ameren also has other subsidiaries that conduct other activities, such as ~~the provision of~~providing shared services. ~~Ameren evaluates competitive electric transmission investment opportunities as they arise.~~ A more detailed description can be found in Note 1 – Summary of Significant Accounting Policies under Part II, Item 8, of this report.

Ameren has four segments: Ameren Missouri, Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Transmission. The Ameren Missouri segment includes all of the operations of Ameren Missouri. Ameren Illinois Electric Distribution consists of the electric distribution business of Ameren Illinois. Ameren Illinois Natural Gas consists of the natural gas business of Ameren Illinois. Ameren Transmission is primarily ~~composed~~consists of the aggregated electric transmission businesses of Ameren Illinois and ATXI. See Note 1516 – Segment Information under Part II, Item 8, of this report for further discussion of Ameren’s ~~Ameren Missouri’s,~~ and Ameren Illinois’ ~~Segments.~~

Ameren’s and Ameren Missouri’s financial statements are prepared on a consolidated basis and therefore include the accounts of ~~its~~their majority-owned subsidiaries. All intercompany transactions have been eliminated. Ameren ~~Missouri and~~Missouri’s subsidiaries were created for the ownership of renewable generation projects. Ameren Illinois ~~have~~has no subsidiaries. All tabular dollar amounts are in millions, unless otherwise indicated.

The following discussion should be read in conjunction with the financial statements contained in this Form 10-K. We intend for this discussion to provide the reader with information that will assist in understanding our financial statements, the changes in certain key items in those financial statements, and the primary factors that accounted for those changes, as well as how certain accounting principles affect our financial statements. The discussion also provides information about the financial results of our business segments to provide a better understanding of how those segments and their results affect the financial condition and results of operations of Ameren as a whole. Discussion regarding our financial condition and results of operations for the year ended December 31, 2020, including comparisons with the year ended December 31, 2021, is included in Item 7 of our Form 10-K for the year ended December 31, 2021, filed with the SEC on February 23, 2022.

In addition to presenting results of operations and earnings amounts in total, we present certain information in cents per diluted share. These amounts reflect factors that directly affect Ameren’s earnings. We believe this per diluted share information helps readers to understand the impact of these factors on Ameren’s earnings per ~~share. All references in this report to earnings per share are based on average~~ diluted ~~common shares outstanding for the relevant period.~~share.

~~Ameren’s strategic plan includes investing in,~~Our core strategy is driven by the following three pillars, which allow us to capitalize on opportunities to benefit our customers, our shareholders, and ~~operating its utilities in, a manner consistent with existing~~the environment:

In February 2023, Ameren Missouri filed an update to its Smart Energy Plan with the MoPSC, which includes a five-year capital investment overview with a detailed one-year plan for 2023. The plan is designed to upgrade Ameren Missouri’s electric infrastructure and includes investments that will upgrade the grid and accommodate more renewable energy. Investments under the plan are expected to total approximately $9.9 billion over the five-year period from 2023 through 2027, with expenditures largely recoverable under the PISA and the RESRAM. Ameren Missouri’s Smart Energy Plan excludes investments in its natural gas distribution business, as well as ~~creating~~removal costs, net of salvage.

In August 2022, Ameren Missouri filed a request with the MoPSC seeking approval to increase its annual revenues for electric service by $316 million. The electric rate increase request is based on a 10.2% ROE, a capital structure composed of 51.9% common equity, a rate base of $11.6 billion, and ~~capitalizing~~a test year ended March 31, 2022, with certain pro-forma adjustments expected through an anticipated true-up date of December 31, 2022. In January 2023, the MoPSC staff recommended an increase to Ameren Missouri's annual electric service revenues of $199 million based on ~~opportunities~~a 9.59% ROE, a capital structure composed of 51.84% common equity, and a rate base as of June 30, 2022, of $10.5 billion. Ameren Missouri expects the MoPSC staff will update its rate base estimate through the anticipated true-up date of December 31, 2022. The MoPSC staff’s recommendation includes an adjustment to annual electric service revenues for ~~investment~~estimated true-up items from June 30, 2022, to December 31, 2022, including the impacts of any investments made during that period. The MoPSC proceeding

Missouri Senate Bill 745 became effective on August 28, 2022. The law extended Ameren Missouri’s PISA election through December 2028 and allows for an additional extension through December 2033 if requested by Ameren Missouri and approved by the ~~benefit~~MoPSC, among other things. The law established a 2.5% annual limit on increases to the electric service revenue requirement used to set customer rates due to the inclusion of ~~its~~incremental PISA deferrals in the revenue requirement. The limitation will be effective for revenue requirements approved by the MoPSC after January 1, 2024, and will be based on the revenue requirement established in the immediately preceding rate order. The current rate limitation, which is effective through 2023, is a 2.85% cap on the compound annual growth rate in the average overall customer rate per kilowatthour, based on the electric rates that became effective in April 2017, less half of the annual savings from the TCJA that was passed on to customers and shareholders. Ameren remains focused on disciplined cost management and strategic capital allocation. In 2017, Ameren continued to allocate significant amounts of capital to those businesses that are supported by constructive regulatory frameworks. It invested $1.4 billion of capital expendituresas approved in ~~its FERC rate-regulated electric transmission and Illinois~~a July 2018 MoPSC order. The law also established electric and natural gas ~~distribution businesses.~~property tax trackers that allow Ameren Missouri to defer the difference between actual property taxes incurred and related taxes included in customer rates as a regulatory asset or regulatory liability, with the difference expected to be reflected in rate base in a subsequent rate order. Upon the effective date of the law, Ameren Missouri began deferring amounts under these trackers. In the 2022 electric service regulatory rate review discussed above, Ameren Missouri requested recovery of the amounts deferred under the electric property tax tracker.

Under an MYRP, the IETL permits any initial rate increase ~~limitations. The plan also provides for expanding renewable generation, retiring coal-fired energy centers as they reach~~to be phased in, with at least 50% of the ~~end of their useful lives, expanding customer energy-efficiency programs, and adding cost-effective demand response programs. The new renewable energy sources identified~~first annual period’s approved rate increase reflected in ~~Ameren Missouri’s plan could represent incremental investments of approximately $1 billion through 2020. In connection~~rates in the first annual period, with the ~~integrated resource plan filing, Ameren Missouri established a goal of reducing CO~~₂ ~~emissions 80% by~~

In September 2022, the ~~equity return~~ICC issued an order approving total ROE incentives and penalties under an MYRP of 24 basis points, allocated among seven performance metrics. These performance metrics include improvements in service reliability in both the frequency and duration of outages, a reduction in peak loads, an increased percentage of spend with diverse suppliers, a reduction in disconnections for certain customers, and improved timeliness in response to customer requests for interconnection of distributed energy resources. These performance metrics and the ROE incentives and penalties will apply annually from 2024 through 2027 under the MYRP filed by Ameren Illinois.

The IRA was enacted in August 2022. The law extends federal production and investment tax credits for projects beginning construction through 2024 and creates new federal production and investment tax credits for projects placed in service after 2024, among other things. The federal production and investment tax credits will support Ameren’s net-zero carbon emission goals and Ameren Missouri’s 2022 Change to the 2020 IRP, incentivize electrification, and enhance customer affordability during Ameren’s transition to clean energy. In addition, the new law imposes a 15% minimum tax on adjusted financial statement income, as defined in the law, assessed against corporations whose average annual adjusted financial statement income exceeds $1 billion for three consecutive preceding tax years, effective for tax years beginning after December 31, 2022. Once a corporation exceeds this three-year average annual adjusted financial statement income threshold, it will be subject to the minimum tax for all future tax years. See Note 12 – Income Taxes under Part II, Item 8, of this report for additional information.

In ~~October 2017,~~February 2022, Ameren’s board of directors increased the quarterly common stock dividend to ~~45.75~~59 cents per share, resulting in an annualized equivalent dividend rate of ~~$1.83~~$2.36 per share. In February 2023, Ameren’s board of directors increased the quarterly common stock dividend to 63 cents per share, resulting in an annualized equivalent dividend rate of $2.52 per share.

Net income attributable to Ameren common shareholders ~~from continuing operations~~ was ~~$523~~$1,074 million, or ~~$2.14~~$4.14 per diluted share, for ~~2017,~~2022, and ~~$653~~$990 million, or ~~$2.68~~$3.84 per diluted share, for ~~2016.~~2021. Net income was favorably affected in 2022, compared with 2021, by increased infrastructure investments across all business segments and a higher recognized ROE at Ameren Illinois Electric Distribution, increased retail electric sales volumes at Ameren Missouri, primarily resulting from colder winter and warmer summer temperatures experienced in 2022, and increased base rate revenues at Ameren Missouri pursuant to the December 2021 MoPSC electric rate order. Net income was unfavorably affected in ~~2017,~~2022, compared with ~~2016,~~2021, by increased ~~income tax expense~~other operations and maintenance expenses not subject to formula rates, riders, or trackers, primarily due to ~~a noncash charge~~an increase due to ~~earnings for~~ the ~~revaluation~~expiration of ~~deferred taxes primarily~~contracts relating to refined coal tax credits at Ameren ~~(parent) as~~Missouri in 2021, a ~~result of the TCJA and the increase~~reduction in the ~~Illinois income tax rate.~~cash surrender value of COLI, and increased Callaway Energy Center costs. Earnings in 2022, compared with 2021, were also unfavorably affected ~~in 2017, compared with 2016, by decreased demand, primarily at Ameren Missouri, due to milder temperatures in 2017, by the absence in 2017 of the MEEIA 2013 performance incentive, and~~ by increased ~~depreciation~~financing costs from debt issuances and amortization expenses at Ameren Missouri. Net income was favorably affected in 2017, compared with 2016, by an increase in base rates, and lower base level of expenses at Ameren Missouri, pursuant to the MoPSC’s March 2017 electric rate order, and by increased investments in infrastructure at the Ameren Illinois Electric Distribution and Ameren Transmission segments, which reflect Ameren’s strategy to allocate incremental capital to those businesses.

At December 31, ~~2017,~~2022, Ameren, on a consolidated basis, had available liquidity in the form of cash on hand and amounts available under the Credit Agreements of ~~$1.6~~$1.5 billion.

~~Capital Expenditures~~Ameren has an ATM program under which Ameren may offer and sell from time to time common stock, which includes the ability to enter into forward sales agreements, subject to market conditions and other factors. As of December 31, 2022, Ameren had approximately $1 billion of common stock available for sale under the ATM program, which takes into account the forward sale agreements in effect as of December 31, 2022. For information regarding long-term debt issuances and maturities, common stock issuances, and outstanding forward sale agreements entered into under the ATM program through the date of this report, see Note 5 – Long-term Debt and Equity Financings under Part II, Item 8, of this report.

Ameren ~~continued to make significant investment in its utility businesses by making~~remains focused on strategic capital allocation. The following chart presents 2022 capital expenditures by segment and the midpoint of ~~$0.8~~projected cumulative capital expenditures for 2023 through 2027 by segment:

For ~~2018~~2023 through ~~2022,~~2027, Ameren’s cumulative capital expenditures are projected to range from ~~$10.5~~$18.9 billion to ~~$11.4~~$20.5 billion. The following table presents the range of projected spending by ~~segment~~segment:

Our results of operations and financial position are affected by many factors. Economic conditions, energy-efficiency investments by our customers and by us, technological advances, distributed generation, and the actions of key customers can significantly affect the demand for our services. Ameren and Ameren Missouri results are also affected by seasonal fluctuations in winter heating and summer cooling demands, as well as by ~~nuclear refueling and other~~ energy center maintenance outages. Additionally, fluctuations in interest rates and conditions in the capital and credit markets affect our cost of borrowing, ~~and~~ our pension and postretirement benefits ~~costs.~~costs, the cash surrender value of COLI, and the asset value of Ameren Missouri’s nuclear decommissioning trust fund. Almost all of Ameren’s revenues are subject to state or federal regulation.

Due to a change in customer behavior and certain business practices resulting from the COVID-19 pandemic, there has been a shift in sales volumes by customer class from pre-pandemic levels at both Ameren Missouri and Ameren Illinois, which began in 2020, with an increase in residential sales, and a decrease in commercial and industrial sales. While our electric sales volumes in 2022, excluding the estimated effects of weather and customer energy-efficiency programs, were comparable to 2021 and, at Ameren Missouri, were comparable to pre-pandemic levels, Ameren Illinois’ sales volumes remain below pre-pandemic levels. However, revenues from Ameren Illinois’ electric distribution business, residential and small nonresidential customers of Ameren Illinois’ natural gas distribution business, and Ameren Illinois’ and ATXI’s electric transmission businesses are decoupled from changes in sales volumes. While our customers are also observing inflationary pressures, those pressures have not significantly affected customer payments. As of December 31, 2022, accounts receivable balances that were 30 days or greater past due or that were a part of a deferred payment arrangement represented 17%, 14%, and 20%, or $107 million, $35 million, and $71 million, of Ameren’s, Ameren Missouri’s, and Ameren Illinois’ customer trade receivables before allowance for doubtful accounts, respectively. In comparison, as of December 31, 2021, these percentages were 20%, 17%, and 24%, or $94 million, $34 million, and $60 million, for Ameren, Ameren Missouri, and Ameren Illinois, respectively. Ameren Illinois’ electric distribution and natural gas distribution businesses have bad debt riders, which provide for recovery of bad debt write-offs, net of any subsequent recoveries. Ameren Missouri does not have a bad debt rider or tracker, and thus its earnings are exposed to increases in bad debt expense, absent regulatory relief.

Ameren Missouri principally uses coal ~~nuclear fuel,~~ and ~~natural gas~~enriched uranium for fuel in its electric operations and purchases natural gas for its customers. Ameren Illinois purchases power and natural gas for its customers. The prices for these commodities can fluctuate significantly because of the global economic and political environment, weather, supply, demand, inflation, and many other factors. ~~As described below, we~~We have natural gas cost recovery mechanisms for our Illinois and Missouri natural gas distribution ~~service~~ businesses, a purchased power cost recovery mechanism for Ameren Illinois’ electric distribution ~~service~~ business, and a FAC for Ameren Missouri’s electric ~~utility~~ business.

We employ various risk management strategies to reduce our exposure to commodity risk and other risks inherent in our business. The reliability of Ameren Missouri’s energy centers and our transmission and distribution systems and the level and timing of operations and maintenance costs and capital investment are key factors that we seek to manage in order to optimize our results of operations, financial position, and liquidity.

The following table presents a summary of Ameren’s earnings for the years ended December 31, ~~2017, 2016,~~2022 and ~~2015:~~

2021:

Earnings per share in 2022, compared with 2021, were favorably affected by:

The cents per share information presented ~~above~~ is based on the ~~diluted average~~weighted-average basic shares outstanding in ~~2016. Pretax amounts~~2021 and does not reflect any change in earnings per share resulting from dilution, unless otherwise noted. Amounts other than variances related to income taxes have been presented net of income taxes using Ameren’s ~~2016~~2022 statutory tax rate of ~~39%.~~

Below is Ameren’s table of income statement components by segment for the years ended December 31, ~~2017, 2016,~~2022 and ~~2015:~~2021:

~~The following table presents the favorable (unfavorable) variations by segment for~~Electric margins are defined as electric revenues less fuel and purchased power costs. Natural gas margins are defined as natural gas ~~margins in 2017 compared with 2016, as well as 2016 compared with 2015.~~revenues less natural gas purchased for resale. We consider electric and natural gas margins useful measures to analyze the change in profitability of our electric and natural gas operations between periods. We have included the analysis below as a complement to the financial information we provide in accordance with GAAP. However, these margins may not be a presentation defined under GAAP, and they may not be comparable to other companies’ presentations or more useful than the GAAP information we provide elsewhere in this report.

The following table presents the favorable (unfavorable) variations by segment for electric and natural gas margins in 2022, compared with 2021:

Ameren’s electric margins increased ~~$105~~$451 million, or 3%11%, in ~~2017~~2022, compared with ~~2016, primarily~~2021, because of increased margins at Ameren ~~Transmission~~Missouri, Ameren Illinois Electric Distribution, and Ameren ~~Missouri.~~Transmission, as discussed below. Ameren’s natural gas margins increased ~~$17~~$64 million, or 3%10%, ~~in 2017 compared with 2016,~~between years primarily because of increased margins at Ameren Illinois Natural ~~Gas.~~

The following items had a favorable effect on Ameren Missouri’s electric margins in ~~2017~~2022, compared with ~~2016:~~2021:

The ~~absence~~following items had a favorable effect on Ameren Illinois Natural Gas’ margins in 2022, compared with 2021:

Ameren Illinois Transmission’s electric margins increased $59 million, or 16%, in 2022, compared with 2021. Base rate revenues were favorably affected by ~~$28 million.~~increased capital investment (+$25 million), as evidenced by a 16% increase in rate base used to calculate the revenue requirement, higher recoverable expenses (+$23 million), the absence in 2022 of the FERC’s March 2021 order (+$7 million), and a higher equity percentage in the capital structure (+$4 million). See Transmission Formula Rate Revisions in Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report for additional information regarding the ~~MEEIA 2013 performance incentive.~~March 2021 FERC order.

Other operations and maintenance expenses ~~decreased $16~~at Ameren increased $163 million in ~~2017~~2022, compared with ~~2016,~~2021. In addition to changes by segment as discussed below, other operations and maintenance expenses increased $22 million in 2022 for activity not reported as part of a segment, as reflected in “Other/Intersegment Eliminations” above, primarily because of ~~items discussed below and~~ an increase in ~~intersegment eliminations~~the elimination of ~~$14 million.~~the non-service cost component of net periodic benefit income at Ameren Services. The non-service cost component of net periodic benefit cost or income at Ameren Services is allocated to the segments and primarily included in the segments’ other operations and maintenance expenses.

Other operations and maintenance expenses ~~increased $3 million in 2017 compared with 2016, primarily because~~were comparable between periods.

~~Other~~The $80 million increase in Ameren Missouri’s other operations and maintenance expenses ~~were $9 million higher~~ in ~~2017~~2022, compared with ~~2016.~~ 2021, was primarily due to the following items:

The following items ~~increased~~partially offset the above increases in other operations and maintenance expenses between years:

Other operations and maintenance expenses ~~decreased $15~~increased $62 million at Ameren Illinois in ~~2017~~2022, compared with ~~2016,~~2021, as discussed below. Other operations and maintenance expenses were comparable at Ameren Illinois Transmission ~~in 2017 compared with 2016.~~between 2022 and 2021.

~~Other~~The $46 million increase in Ameren Illinois Electric Distribution’s other operations and maintenance expenses ~~were $26 million lower~~ in ~~2017~~2022, compared with ~~2016,~~2021, was primarily due to the following items:

The above increases were partially offset by ~~an $11~~a $4 million ~~increase~~reduction in environmental remediation rider costs, ~~and a $3 million increase in labor costs~~primarily resulting from ~~increased wages.~~fewer remediation projects.

Other operations and maintenance expenses ~~were $9~~at Ameren Illinois Natural Gas increased $17 million ~~higher~~ in ~~2017~~2022, compared with ~~2016, primarily because of increased bad debt, customer energy-efficiency, and environmental remediation costs.~~

The $143 million, $100 million, and $42 million increases in depreciation and amortization expenses ~~increased $51 million, $19 million, and $22 million~~ in ~~2017~~2022, compared with ~~2016~~2021, at Ameren, Ameren Missouri, and Ameren Illinois, respectively, were primarily ~~because of additional property, plant, and equipment across their respective segments.~~

Taxes other than income taxes increased ~~$10~~$27 million at Ameren in ~~2017~~2022, compared with ~~2016, as discussed below.~~2021, primarily because of $12 million and $8 million increases in excise taxes at Ameren Missouri and Ameren Illinois Natural Gas, respectively, mostly due to higher base rates at Ameren Missouri, pursuant to the December 2021 MoPSC electric rate order, and increased sales at both segments. Taxes other than income taxes ~~were comparable~~also increased $8 million at Ameren ~~Transmission.~~ Missouri because of increased property taxes, primarily resulting from higher assessed values, that were incurred prior to the implementation of the electric and natural gas property tax trackers beginning in August 2022.

See Excise Taxes in Note 115 – ~~Summary of Significant Accounting Policies~~Supplemental Information under Part II, Item 8, of this report for additional information.

Other income, net, increased $24 million at Ameren ~~Missouri~~

See Note 6 – Other Income, ~~and Expenses~~Net under Part II, Item 8, of this report for additional information. See Note 10 – Retirement Benefits under Part II, Item 8, of this report for more information on the non-service cost components of net periodic benefit income.

Ameren’s ~~2017~~2022 capital expenditures consisted of expenditures made by its subsidiaries, including $69 million by ATXI ~~which~~and other electric transmission subsidiaries. Of the $308 million in capital expenditures spent ~~$289 million primarily on the Illinois Rivers and Spoon River projects.~~by Ameren Illinois Natural Gas during 2022, $183 million related to natural gas projects eligible for QIP recovery. Ameren’s 2021 capital expenditures consisted of expenditures made by its subsidiaries, including $41 million by ATXI and other electric transmission subsidiaries. Of the $278 million in capital expenditures spent ~~$355~~by Ameren Illinois Natural Gas during 2021, $170 million ~~on transmission~~related to natural gas projects ~~$153~~eligible for QIP recovery. In addition, Ameren Missouri expenditures included $525 million ~~on projects that are recovered under~~for wind generation, primarily for the ~~QIP rider, and $123 million on IEIMA projects. Other~~acquisition of the Atchison Renewable Energy Center. In both years, other capital expenditures were made principally to maintain, upgrade, and improve the reliability of the transmission and distribution systems of Ameren Missouri and Ameren Illinois by investing in substation upgrades, energy center projects, and smart-grid technology. Additionally, the Ameren Companies invested in various software projects.

In 2021, the MISO issued a report outlining a preliminary long-range transmission planning roadmap of projects through 2039, which considers the rapidly changing generation mix within MISO resulting from significant additions of renewable generation, actual and expected generation plant closures, and state mandates or goals for ~~qualified~~clean energy or carbon emissions reductions. In July 2022, the MISO approved the first tranche of projects under the first phase of the roadmap. A portion of these projects were assigned to various utilities, of which Ameren was awarded projects that are estimated to cost approximately $1.8 billion, based on the MISO’s cost estimate. Construction on the Ameren projects is expected to begin in 2025, with completion dates expected near the end of this decade. The MISO initiated requests for proposals in December 2022, and is expected to initiate additional requests for proposals in March and July 2023, for additional first tranche projects crossing Missouri, with total cost estimated by the MISO of approximately $0.7 billion, which are expected to be awarded between late-2023 and mid-2024.

In February 2023, Ameren Missouri filed an update to its Smart Energy Plan with the MoPSC, which includes a five-year capital investment overview with a detailed one-year plan for 2023. The plan is designed to upgrade Ameren Missouri’s electric infrastructure and includes investments that will upgrade the grid and accommodate more renewable energy. Investments under the plan are expected to total approximately $9.9 billion over the five-year period from 2023 through 2027, with expenditures largely recoverable under the PISA and the RESRAM. Ameren Missouri’s Smart Energy Plan excludes investments in its natural gas infrastructure under the QIP rider. ATXI’s estimated capital expenditures include expenditures for the three MISO-approved multi-value transmission projects. For additional information regarding the IEIMA capital expenditure requirements, the QIP rider, and ATXI’s transmission projects, see Part I, Item 1,distribution business, as well as removal costs, net of ~~this report.~~salvage.

Ameren Missouri continually reviews its generation portfolio and expected power needs. As a result, Ameren Missouri could modify its plan for generation capacity, the type of generation asset technology that will be employed, and whether capacity or power may be purchased, among other changes. Additionally, we continually review the reliability of our transmission and distribution systems, expected capacity needs, and opportunities for transmission ~~investments.~~investments within and outside our service territories. The timing and amount of investments could vary because of changes in expected capacity, the condition of transmission and distribution systems, and our ability and willingness to pursue transmission investments, as well as our ability to obtain necessary regulatory approvals, among other factors. Any changes in future generation, transmission, or distribution needs could result in significant changes in capital expenditures or losses, which could be material. Compliance with environmental regulations could also have significant impacts on the level of capital expenditures.

Cash provided by, or used in, financing activities is a result of our financing needs, which depend on the level of cash provided by operating activities, the level of cash used in investing activities, the ~~dividends declared by Ameren’s board~~level of ~~directors,~~dividends, and our long-term debt maturities, among other things.

Ameren Missouri’s cash provided by financing activities decreased $278 million during 2022, compared with 2021. During 2022, Ameren Missouri utilized net proceeds of $524 million from the issuance of long-term debt to repay then-outstanding short-term debt and for capital expenditures. In addition, Ameren Missouri utilized proceeds from net commercial paper issuances of $164 million along with cash provided by operating activities to fund, in part, capital expenditures. In comparison, ~~during 2016,~~in 2021, Ameren Missouri utilized net proceeds of $524 million from the issuance of long-term debt to repay then-outstanding short-term debt, including short-term debt incurred in connection with the increased purchases for natural gas for resale and purchased power costs discussed in Cash Flows from Operating Activities. Additionally, proceeds from the issuance of ~~$646~~long-term debt and capital contributions of $207 million from Ameren (parent) were used to fund a portion of ~~long-term indebtedness~~

Ameren Illinois’ cash provided by financing activities decreased ~~by $176~~$149 million ~~in 2016,~~during 2022, compared with ~~2015.~~2021. During ~~2016,~~2022, Ameren Illinois ~~issued $291~~utilized net proceeds of $848 million from the issuance of long-term debt to repay $400 million of maturities of long-term ~~indebtedness~~debt and ~~net commercial paper issuances and utilized the proceeds~~ to repay ~~at maturity $129 million~~a portion of ~~higher-cost long-term indebtedness. In comparison, during 2015, Ameren Illinois utilized~~the then-outstanding short-term debt. Additionally, the proceeds from the issuance of ~~$248 million of~~ long-term ~~indebtedness to repay $32 million of~~debt, proceeds from net commercial paper issuances of $161 million, capital contributions from Ameren (parent) of $15 million, and cash provided by operating activities were used to fund, in part, ~~investing activities. Additionally,~~capital expenditures. In comparison, in ~~2016~~2021, Ameren Illinois ~~paid $110~~utilized net proceeds of $449 million from the issuance of long-term debt to repay then-outstanding short-term debt, including short-term debt incurred in ~~dividends to~~connection with the increased purchases for natural gas for resale and purchased power costs discussed in Cash Flows from Operating Activities. Additionally, the proceeds from the issuance of long-term debt and $262 million of capital contributions from Ameren (parent) ~~compared~~were used to ~~no dividends paid~~fund, in ~~the year-ago period.~~part, capital expenditures. In 2021 Ameren Illinois also received $103 million from commercial paper issuances. In addition, Ameren Illinois repaid $19 million of money pool borrowings and redeemed $13 million of preferred stock in 2021.

The liquidity needs of the Ameren ~~Ameren Missouri, and Ameren Illinois~~Companies are typically supported through the use of available cash, drawings under committed credit agreements, commercial paper issuances, and/or, ~~proceeds from~~in the case of Ameren Missouri and Ameren Illinois, short-term affiliate ~~borrowings, drawings under the Credit Agreements, or commercial paper issuances.~~borrowings. See Note 4 – Short-term Debt and Liquidity under Part II, Item 8, of this report for additional information on credit agreements, ~~short-term affiliate borrowing activity,~~ commercial paper issuances, ~~relevant interest rates, and borrowings under~~ Ameren’s money pool ~~arrangements.~~arrangements and related borrowings, and relevant interest rates.

The following table presents Ameren’s consolidated net available liquidity as of December 31, ~~2017~~:2022:

In December 2022, the Credit Agreements, which were scheduled to mature in December 2025, were extended and now mature in December 2027. The Credit Agreements provide ~~$2.1~~$2.6 billion of credit ~~cumulatively~~ through ~~maturity in~~ December ~~2021. The maturity date may be extended~~2027. See Note 4 – Short-term Debt and Liquidity under Part II, Item 8, of this report for ~~two~~ additional ~~one-year periods upon mutual consent of the borrowers and lenders. Borrowings by Ameren (parent) under either of~~information on the Credit ~~Agreements are due and payable no later than~~Agreements. During the maturity date, while borrowings by Ameren Missouri and Ameren Illinois are due and payable no later than the earlier of the maturity date or 364 days after the date of such borrowing (subject to the right of each borrower to re-borrow in accordance with the terms of the applicable Credit Agreement). The Credit Agreements are used to borrow cash, to issue letters of credit, and to support issuances under Ameren (parent)’s, Ameren Missouri’s, and Ameren Illinois’ commercial paper programs. Both of the credit agreements are available to Ameren (parent) to support issuances under Ameren (parent)’s commercial paper program, subject to available credit capacity under the agreements. The Missouri Credit Agreement is available to support issuances under Ameren Missouri’s commercial paper program. The Illinois Credit Agreement is available to support issuances under Ameren Illinois’ commercial paper program. Issuances under theyear ended December 31, 2022, Ameren (parent), Ameren Missouri, and Ameren Illinois each issued commercial ~~paper programs were available at lower interest rates than the interest rates of borrowings~~paper. Borrowings under the Credit ~~Agreements. Commercial~~Agreements and commercial paper issuances ~~were thus preferred to credit facility borrowings as a source~~are based upon available interest rates at that time of ~~third-party short-term debt.~~the borrowing or issuance.

Ameren has a money pool agreement with and among its utility subsidiaries to coordinate and to provide for certain short-term cash and working capital requirements. As short-term capital needs arise, and based on availability of funding sources, Ameren Missouri and Ameren Illinois will access funds from the utility money pool, the Credit Agreements, or the commercial paper programs depending on which option has the lowest interest rates. ~~See Note 4 – Short-term Debt and Liquidity under Part II, Item 8, of this report for a detailed explanation of the utility money pool arrangement.~~

The issuance of short-term debt securities by Ameren’s utility subsidiaries is subject to FERC approval ~~by the FERC~~ under the Federal Power Act. In ~~June 2017, the FERC issued an order authorizing ATXI to issue up to $300 million of short-term debt securities through July 2019. In 2016,~~January 2023, the FERC issued orders authorizing Ameren Missouri, ~~and~~ Ameren Illinois, and ATXI to ~~each~~ issue up to $1 billion, $1 billion, and $300 million, respectively, of short-term debt securities through ~~March 2018 and through September 2018, respectively.~~January 2025.

The Ameren Companies continually evaluate the adequacy and appropriateness of their liquidity arrangements for changing business conditions. When business conditions warrant, changes may be made to existing credit agreements or to other short-term borrowing ~~arrangements.~~arrangements, or other arrangements may be made.

The following table presents ~~our~~Ameren’s issuances (net of any issuance premiums or discounts), of long-term debt and equity, as well as redemptions ~~repurchases,~~ and maturities of long-term debt and preferred stock for the years ended December 31, ~~2017~~, ~~2016~~,2022 and ~~2015. The Ameren Companies did not issue any common stock or redeem or repurchase any preferred stock during the years ended~~ ~~2017~~, ~~2016, and~~ ~~2015~~. In 2017, 2016, and 2015, Ameren Missouri received cash capital contributions as a result of the tax allocation agreement from Ameren (parent). In 2017 and 2015, Ameren Illinois received cash capital contributions from Ameren (parent).2021. For additional information related to the terms and uses of these issuances and effective registration statements, and Ameren’s forward sale agreements relating to common stock, see Note 5 – Long-term Debt and Equity Financings under Part II, Item 8, of this report.

The Ameren Companies may sell securities registered under their effective registration statements if market conditions and capital requirements warrant such sales. Any offer and sale will be made only by means of a prospectus that meets the requirements of the Securities Act of 1933 and the rules and regulations thereunder.

At December 31, ~~2017,~~2022, the Ameren Companies were in compliance with the provisions and covenants contained within their credit agreements, indentures, and articles of incorporation, as applicable, and ATXI was in compliance with the provisions and covenants contained in its note purchase ~~agreement.~~agreements. See Note 4 – Short-term Debt and Liquidity and Note 5 – Long-term Debt and Equity Financings under Part II, Item 8, of this report for a discussion of covenants and provisions (and applicable cross-default provisions) contained in our credit agreements, certain of the Ameren Companies’ indentures and articles of incorporation, and ATXI’s note purchase ~~agreement.~~agreements.

We consider access to short-term and long-term capital markets to be a significant source of funding for capital requirements not satisfied by cash provided by our operating activities. Inability to raise capital on reasonable terms, particularly during times of uncertainty in the capital markets, could negatively affect our ability to maintain and expand our businesses. After assessing its current operating performance, liquidity, and credit ratings (see Credit Ratings below), Ameren, Ameren Missouri, and Ameren Illinois each believes that it will continue to have access to the capital ~~markets.~~markets on reasonable terms. However, events beyond Ameren’s, Ameren Missouri’s, and Ameren Illinois’ control may create uncertainty in the capital markets or make access to the capital markets uncertain or limited. Such events could increase our cost of capital and adversely affect our ability to access the capital markets.

Ameren paid to its shareholders common stock dividends totaling ~~$431~~$610 million, or ~~$1.778~~$2.36 per share, in ~~2017, $416~~2022 and $565 million, or ~~$1.715~~$2.20 per share, in ~~2016, and $402 million, or $1.655 per share, in 2015.~~

Certain of our financial agreements and corporate organizational documents contain covenants and conditions that, among other things, restrict the Ameren Companies’ payment of dividends in certain circumstances.

Ameren Illinois’ articles of incorporation require its dividend payments on common stock to be based on ratios of common stock to total capitalization and other provisions with respect to certain operating expenses and accumulations of earned surplus. Additionally, Ameren has committed to the FERC to maintain a minimum of 30% equity in ~~its~~the capital structure at Ameren Illinois.

Ameren Missouri and Ameren Illinois, as well as certain other nonregistrant Ameren subsidiaries, are subject to Section 305(a) of the Federal Power Act, which makes it unlawful for any officer or director of a public utility, as defined in the Federal Power Act, to participate in the making or paying of any dividend from any funds “properly included in capital account.” The FERC has consistently interpreted the provision to allow dividends to be paid as long as (1) the source of the dividends is clearly disclosed, (2) the dividends are not excessive, and (3) there is no self-dealing on the part of corporate officials. At a minimum, Ameren believes that dividends can be paid by its subsidiaries that are public utilities from net income and from retained earnings. In addition, under Illinois law, Ameren Illinois and ATXI may not pay any dividend on ~~its~~their respective stock unless, among other things, ~~its~~their respective earnings and earned surplus are sufficient to declare and pay a dividend after ~~provision is~~provisions are made for reasonable and proper reserves, or unless Ameren Illinois or ATXI has specific authorization from the ICC.

At December 31, ~~2017,~~2022, the amount of restricted net assets of Ameren’s subsidiaries that may not be distributed to Ameren in the form of a loan or dividend was ~~$2.3~~$4.0 billion.

The following table presents common stock dividends declared and paid by Ameren Corporation to its common shareholders and by Ameren ~~Missouri and Ameren Illinois~~subsidiaries to their parent, Ameren:

Ameren Missouri and Ameren Illinois each have issued preferred stock, which ~~provides~~provide for cumulative ~~preferred stock~~ dividends. Each company’s board of directors considers the declaration of ~~the~~ preferred stock dividends to shareholders of record on a certain date, stating the date on which the dividend is payable and the amount to be paid. See Note 5 – Long-term Debt and Equity Financings under Part II, Item 8, of this report for further detail concerning the preferred stock issuances.

Ameren’s and Ameren Missouri’s financial statements are prepared on a consolidated basis and therefore include the accounts of ~~its~~their majority-owned subsidiaries. All intercompany transactions have been eliminated. Ameren ~~Missouri and~~Missouri’s subsidiaries were created for the ownership of renewable generation projects. Ameren Illinois ~~have~~has no subsidiaries. All tabular dollar amounts are in millions, unless otherwise indicated. ~~Unless otherwise stated, these notes to the financial statements exclude discontinued operations for all periods presented.~~

Our accounting policies conform to GAAP. Our financial statements reflect all adjustments (which include normal, recurring adjustments) that are necessary, in our opinion, for a fair presentation of our results. The preparation of financial statements in conformity with GAAP requires management to make certain estimates and assumptions. Such estimates and assumptions affect reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the dates of financial statements, and the reported amounts of revenues and expenses during the reported periods. Actual results could differ from those estimates.

WeOur customer rates are regulated by the MoPSC, the ICC, and the FERC. We defer certain costs as assets pursuant to actions of rate regulators or because of expectations that we will be able to recover such costs in future rates charged to customers. We also defer certain amounts as liabilities pursuant to actions of rate regulators or based on the expectation that such amounts will be ~~returned~~refunded to customers in future rates. Regulatory assets and liabilities are amortized consistent with the period of expected regulatory treatment. Ameren Missouri and Ameren Illinois have various rate-adjustment mechanisms in place that provide for the recovery of purchased natural gas and electric fuel and purchased power costs without a traditional regulatory rate review.

~~The Ameren Illinois asbestos-related litigation rider includes a trust fund. At December 31, 2017 and 2016,~~We continually assess the ~~trust fund balance~~recoverability of ~~$23 million and $22 million, respectively, was reflected in “Other assets” on Ameren’s and Ameren Illinois’ balance sheets. This balance~~our respective regulatory assets. Regulatory assets are charged to earnings when it is restricted only for the use of funding certain asbestos-related claims. The rider is subject to the following terms: 90% of the cash expenditures in excess of the amount included in base electric rates is tono longer probable that such amounts will be recovered ~~from~~through future revenues. To the ~~trust fund. If cash expenditures~~extent that refunds to customers related to regulatory liabilities are ~~less than~~no longer probable, the ~~amount in base rates, Ameren Illinois will contribute 90% of the difference~~amounts are credited to ~~the trust fund.~~earnings.

Cash and cash equivalents include ~~cash on hand and temporary~~short-term, highly liquid investments purchased with an original maturity of three months or less. Cash and cash equivalents subject to legal or contractual restrictions and not readily available for use for general corporate purposes are classified as restricted cash. See Note 15 – Supplemental Information for a reconciliation of cash, cash equivalents, and restricted cash reported within the balance sheets and the statements of cash flows.

The allowance for doubtful accounts represents our estimate of existing accounts receivable that will ultimately be uncollectible. The allowance is calculated by applying estimated loss factors to various classes of outstanding receivables, including unbilled revenue. The loss factors used to estimate uncollectible accounts are based upon both historical collections experience and management’s estimate of future collections success given the existing and anticipated future collections environment. Ameren Illinois has a bad debt ~~rider~~riders that ~~adjusts~~adjust rates for net write-offs of customer accounts receivable above or below those being collected in rates. In 2020, the rider for electric distribution allowed for recovery of bad debt expense recognized under GAAP.

Inventories are recorded at the lower of weighted-average cost or net realizable value. Inventories are capitalized when purchased and then expensed as consumed or capitalized as property, plant, and equipment when installed, as appropriate. ~~The following table presents a breakdown~~See Note 15 – Supplemental Information for the components of ~~inventories for each of the Ameren Companies at~~ ~~December 31, 2017~~ ~~and~~ ~~2016~~:

Ameren Missouri’s cost of nuclear fuel is capitalized as a part of “Property, Plant, and Equipment, Net” on Ameren and Ameren Missouri’s balance sheets and then amortized to “Operating Expenses – Fuel” in their respective statements of income on a unit-of-production basis. Nuclear fuel amortization is reflected as a part of “Depreciation and amortization” on their respective statements of cash flow.

When it becomes probable an asset will be retired significantly in advance of its previously expected useful life and in the near term, the Ameren Companies must assess the probability of full recovery of the remaining net book value of the asset to be abandoned. We recognize a loss on abandonment when it becomes probable that all or part of the cost of an asset, including a return at the applicable WACC, will be disallowed from recovery either through customer rates or through the issuance of securitized utility tariff bonds and such amount is reasonably estimable. An abandonment loss, if any, would equal the difference between the remaining net book value of the asset and the present value of the expected future cash flows. If the asset is still in service, the net book value is classified as plant to be abandoned, net, within “Property, Plant, and Equipment, Net” on the balance sheet. The net book value will be classified as a regulatory asset on the balance sheet when the asset is no longer in service or as required by a rate order.

In relation to the NSR and Clean Air Act litigation discussed in Note 14 – Commitments and Contingencies, in December 2021, Ameren Missouri filed a motion with the United States District Court for the Eastern District of Missouri to modify a previously issued remedy order to allow the retirement of the Rush Island Energy Center in lieu of installing a flue gas desulfurization system. As of December 31, 2022 and 2021, Ameren and Ameren Missouri determined that the Rush Island Energy Center met the criteria to be considered probable of abandonment and have classified its remaining net book value as plant to be abandoned, net, within “Property, Plant, and Equipment, Net” on Ameren’s and Ameren Missouri’s balance sheets. See Note 3 – Property, Plant, and Equipment, Net for our plant to be abandoned balance as of December 31, 2022 and 2021. Ameren Missouri is currently allowed a full recovery of and a full return on its investment in Rush Island Energy Center and has concluded that no abandonment loss was required as of December 31, 2022 and 2021. As part of the assessment of any potential future abandonment loss, consideration will be given to rate and securitization orders issued by the MoPSC to Ameren Missouri and to orders issued to other Missouri utilities with similar facts. See Note 2 – Rate and Regulatory Matters for the MoPSC staff’s recommedation related to Rush Island in Ameren Missouri’s 2022 electric service regulatory rate review.

Depreciation is provided over the estimated lives of the various classes of depreciable property by applying composite rates on a straight-line basis to the cost basis of such property. The composite rates include a provision for the estimated removal cost of property, plant, and equipment retired from service, net of salvage. The provision for depreciation for the Ameren Companies in ~~2017, 2016,~~2022, 2021, and ~~2015~~ 2020

WeAs a part of “Property, Plant, and Equipment, Net” on the balance sheet, we capitalize allowance for funds used during construction, orwhich is the cost of borrowed funds and the cost of equity funds (preferred and common shareholders’ equity) applicable to eligible rate-regulated construction ~~expenditures,~~work in progress, in accordance with the utility industry’s accounting ~~practice.~~ practice and GAAP. The amount of allowance for funds used during construction is calculated using a FERC-prescribed formula based on a rate, which incorporates the average cost of short-term debt, the average cost of long-term debt, and the cost of equity funds. The portion attributable to borrowed funds is recorded as a reduction of “Interest Charges” on the statements of income. The portion attributable to equity funds is recorded within “Other Income, Net” on the statements of income. This accounting practice offsets the effect on earnings of the cost of financing during construction. See Note 15 – Supplemental Information for the amount of allowance for funds used during construction capitalized and the average rate applied to eligible construction work in progress.

Allowance for funds used during construction does not represent a current source of cash funds. This accounting practice offsets the effect on earnings of the cost of financing during construction, and it treats such financing costs in the same manner as construction charges for labor and materials.

Goodwill represents the excess of the purchase price of an acquisition over the fair value of the net assets acquired. Ameren and Ameren Illinois had goodwill of $411 million at December 31, ~~2017~~2022 and ~~2016.~~2021. Ameren has four reporting units: Ameren Missouri, Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Transmission. Ameren Illinois has three reporting units: Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Illinois Transmission. Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Illinois Transmission had goodwill of $238 million, $80 million, and $93 million, respectively, at December 31, ~~2017~~2022 and ~~2016.~~2021. The Ameren Transmission reporting unit had the same $93 million of goodwill as the Ameren Illinois Transmission reporting unit at December 31, ~~2017~~2022 and ~~2016.~~2021.

Ameren and Ameren Illinois evaluate goodwill for impairment in each of their reporting units as of October 31 each year, or more frequently if events ~~and~~occur or circumstances change that would more likely than not reduce the fair value of their reporting units below their carrying amounts. To determine whether the fair value of a reporting unit is more likely than not greater than its carrying amount, Ameren and Ameren Illinois elect to perform either a qualitative assessment or to bypass the qualitative assessment and perform a quantitative test, on an annual basis. On December 31, 2016, due to a change in reporting units, Ameren and Ameren Illinois performed a quantitative test and determined that the estimated fair value of each reporting unit significantly exceeded its respective carrying value as of that date. Based on these results, test.

Ameren and Ameren Illinois elected to perform a qualitative assessment for their annual goodwill impairment test conducted as of October 31, ~~2017.~~

We evaluate long-lived assets classified as held and used for impairment when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. Whether an impairment has occurred is determined by comparing the estimated undiscounted cash flows attributable to the assets to the carrying value of the assets. If the carrying value exceeds the undiscounted cash flows, we recognize an impairment charge equal to the amount by which the carrying value exceeds the estimated fair value of the assets. In the period in which we determine that an asset meets held for sale criteria, we record an impairment charge to the extent the book value exceeds its estimated fair value less cost to sell. We did not identify any events or changes in circumstances that indicated that the carrying value of long-lived assets may not be recoverable in ~~2017~~2022, 2021, or 2020.

Liabilities for environmental costs are recorded on an undiscounted basis when it is probable that a liability has been incurred and the amount of the liability can be reasonably estimated. Costs are expensed or deferred as a regulatory asset when it is expected that the costs will be recovered from customers in future rates. See Note 14 – Commitments and Contingencies for additional information on liabilities for environmental costs.

Estimated funds collected from customers to pay for the future removal ~~costs that do not constitute legal obligations are classified as~~cost of property, plant, and equipment retired from service, net of salvage, represent a cost of removal regulatory ~~liabilities.~~liability. See the cost of removal regulatory liability balance in Note 2 – Rate and Regulatory Matters.

Ameren and Ameren Illinois have COLI, which is recorded at the net cash surrender value. The ~~following table provides a reconciliation of~~net cash surrender value is the ~~beginning and ending carrying~~ amount ~~of AROs for~~that can be realized under the ~~years ended December 31, 2017 and 2016:~~

~~The Ameren Companies~~We record ~~operating revenue~~revenues from contracts with customers for various electric orand natural gas ~~service~~services, which primarily consist of retail distribution, electric transmission, and off-system arrangements. When more than one performance obligation exists in a contract, the consideration under the contract is allocated to the performance obligations based on the relative standalone selling price.

Electric and natural gas retail distribution revenues are earned when itthe commodity is delivered to our customers. We accrue an estimate of electric and natural gas retail distribution revenues for service ~~rendered~~provided but unbilled at the end of each accounting period. Electric transmission revenues are earned as electric transmission services are provided. Off-system revenues are primarily comprised of MISO revenues and wholesale bilateral revenues. MISO revenues include the sale of electricity, capacity, and ancillary services. Wholesale bilateral revenues include the sale of electricity and capacity. MISO-related electricity and wholesale bilateral electricity revenues are earned as electricity is delivered. Capacity and ancillary service revenues are earned as services are provided.

~~Ameren Illinois participates in~~Retail distribution, electric transmission, and off-system revenues, including the ~~performance-based formula ratemaking framework pursuant~~underlying components described above, represent a series of goods or services that are substantially the same and have the same pattern of transfer over time to our customers. Revenues from contracts with customers are equal to the ~~IEIMA~~amounts billed and our estimate of electric and natural gas retail distribution services provided but unbilled at the ~~FEJA. In addition, Ameren Illinois’~~end of each accounting period. Customers are billed at least monthly, and ~~ATXI’s electric transmission service operating~~payments are due less than one month after goods and/or services are provided. See Note 16 – Segment Information for disaggregated revenue information.

For certain regulatory recovery mechanisms that are alternative revenue programs rather than revenues from contracts with customers, we recognize revenues that have been authorized for rate recovery, are ~~regulated by the FERC. The provisions~~objectively determinable and probable of ~~the IEIMA~~recovery, and ~~the FERC’s electric transmission formula rate framework provide for annual reconciliations~~are expected

As of December 31, 2022 and 2021, our remaining performance obligations were immaterial. The Ameren Companies elected not to reflect that year’s actual revenue requirement. The regulatory balance is then collected from, or refunded to, customers within two years. See Note 2 – Rate and Regulatory Matters for information regarding Ameren Illinois’ revenue requirement reconciliation pursuantdisclose the aggregate amount of the transaction price allocated to the ~~IEIMA.~~performance obligations that are unsatisfied as of the end of the reporting period for contracts with an initial expected term of one year or less.

MISO-related purchase and sale transactions are recorded by Ameren, Ameren Missouri, and Ameren Illinois using settlement information provided by the MISO. Ameren Missouri records these purchase and sale transactions on a net hourly position. Ameren Missouri records net purchases in a single hour in “Operating Expenses – Purchased power” and net sales in a single hour in “Operating Revenues – Electric” in its statement of income. Ameren Illinois records net purchases in “Operating Expenses – Purchased power” in its statement of income to reflect all of its MISO transactions relating to the procurement of power for its customers. On occasion, Ameren Missouri’s and Ameren Illinois’ prior-period transactions will be resettled outside the routine settlement process because of a change in the MISO’s tariff or a material interpretation thereof. In these cases, Ameren Missouri and Ameren Illinois recognize revenues and expenses associated with resettlements once the resettlement is probable and the resettlement amount can be estimated. ~~Revenues are recognized once the resettlement amount is received.~~ There were no material MISO resettlements in ~~2017, 2016,~~2022, 2021, or ~~2015.~~

Stock-based compensation cost is measured at the grant date based on the fair value of the award, net of an assumed forfeiture rate. Ameren recognizes as compensation expense the estimated fair value of stock-based compensation on a straight-line basis over the requisite vesting period. To the extent that actual forfeitures differ from estimated forfeitures, such differences are accounted for as an adjustment to compensation expense and recorded in the period that estimates are revised. Compensation cost is ultimately recognized only for awards for which the requisite service was provided. See Note 11 – Stock-based Compensation for additional information.

Long-term debt discounts, premiums, and issuance costs are amortized over the lives of the related issuances. Credit agreement fees are amortized over the term of the agreement.

Ameren uses an asset and liability approach for its financial accounting and reporting of income taxes. Deferred tax assets and liabilities are recognized for transactions that are treated differently for financial reporting and income tax return purposes. These deferred tax assets and liabilities are based on statutory tax rates.

We expect that regulators will reduce future revenues for deferred tax liabilities that were initially recorded at rates in excess of the current statutory rate. Therefore, reductions in certain deferred tax liabilities that were recorded because of decreases in the statutory rate have been credited to a regulatory liability. A regulatory asset has been established to recognize the probable recovery through future customer rates of tax benefits related to the equity component of allowance for funds used during construction, as well as the effects of tax rate increases. To the extent deferred tax balances are included in rate base, the revaluation of deferred taxes is recorded as a regulatory asset or liability on the balance sheet and will be collected from, or refunded to, customers. For deferred tax balances not included in rate base, the revaluation of deferred taxes is recorded as an adjustment to income tax expense on the income statement. ~~See Note 12 – Income Taxes for further information regarding both the revaluation of deferred taxes related to the TCJA.~~

Ameren Missouri, Ameren Illinois, and all the other Ameren subsidiary companies are parties to a tax allocation agreement with Ameren (parent) that provides for the allocation of consolidated tax liabilities. The tax allocation agreement specifies that each ~~party~~subsidiary be allocated an amount of tax using a stand-alone calculation ~~which is similar~~ratio to ~~that which would be~~the total amount of tax owed ~~or refunded had~~by the ~~party been separately subject to tax considering the impact of consolidation.~~consolidated group. Any net benefit attributable to Ameren (parent) is reallocated to the other ~~parties.~~subsidiaries. This reallocation is treated as a capital contribution to the ~~party~~subsidiary receiving the benefit. See Note 13 – Related-party Transactions for information regarding capital contributions under the tax allocation agreement.

Below is a summary of our regulatory frameworks and significant regulatory proceedings and related lawsuits. We are unable to predict the ultimate outcome of these matters, the timing of final decisions of the various agencies and courts, or the effect on our results of operations, financial position, or liquidity.

The following table presents the regulatory frameworks and significant regulatory recovery mechanisms for each of Ameren’s rate-regulated businesses, which are discussed in more detail below:

~~March 2017 Electric Rate Order~~

Ameren Missouri has recovery mechanisms, including the RESRAM, FAC, MEEIA, PGA, and WNAR, that allow customer rates to be adjusted without a traditional regulatory rate review. These riders, along with the PISA, each described in more detail below, partially mitigate the effects of regulatory lag. Ameren Missouri also employs other recovery mechanisms, including a renewable energy standard cost tracker, as well as electric and natural gas trackers for uncertain income tax positions, certain excess deferred income taxes, property taxes, and pension and postretirement benefit costs. Each of these trackers allows Ameren Missouri to defer the difference between actual costs incurred and costs included in customer rates as a regulatory asset or regulatory liability, with the difference expected to be reflected in base rates in a subsequent MoPSC rate order. Ameren Missouri’s cost recovery under any of its recovery mechanisms is subject to MoPSC prudence reviews.

The PISA permits Ameren Missouri to defer and recover 85% of the depreciation expense for investments in qualifying property, plant, and equipment placed in service and not included in base rates. Investments not eligible for recovery under the PISA include amounts related to new nuclear and natural gas generating units and service to new customer premises. Additionally, the PISA permits Ameren Missouri to earn a return at the applicable WACC on rate base that incorporates those qualifying investments, as well as changes in total accumulated depreciation excluding retirements and plant-related deferred income taxes since the previous regulatory rate review. The regulatory asset for accumulated PISA deferrals also earns a return at the applicable WACC until added to rate base prospectively. Ameren Missouri recognizes an offset to interest charges for its cost of debt relating to each return allowed under the PISA, with the difference between the applicable WACC and its cost of debt recognized in revenues when recovery of PISA deferrals is reflected in customer rates. Approved PISA deferrals are recovered over a period of 20 years following a regulatory rate review. Additionally, under the RESRAM, Ameren Missouri is permitted to recover the 15% of depreciation expense not recovered under the PISA, and earn a return at the applicable WACC for investments in renewable generation plant placed in service to comply with Missouri’s renewable energy standard. The RESRAM deferrals are a regulatory asset until they are included in customer rates and collected in a subsequent period. Those investments not eligible for recovery under the PISA and the remaining 15% of certain property, plant, and equipment placed in service, unless eligible for recovery under the RESRAM, remain subject to regulatory lag. Under Missouri law, as a result of the PISA election, additional provisions apply to Ameren Missouri. These provisions include limiting Ameren Missouri’s rate increases to a 2.85% compound annual growth rate in the average overall customer rate

The RESRAM permits Ameren Missouri to recover or refund, through customer rates, the difference between the cost of compliance, net of federal production and investment tax credits, with Missouri’s renewable energy standard and the amount set in base ~~level~~rates. Effective February 28, 2022, all sales from the High Prairie Renewable and Atchison Renewable energy centers are included in the RESRAM. Previously, 95% of ~~expenses,~~these sales were included in the FAC and ~~amortizations~~5% were included in the RESRAM. Customer rates are adjusted for the RESRAM on an annual basis without a traditional regulatory rate review, subject to MoPSC prudence reviews. The difference between actual compliance costs and costs billed to customers in a given period is deferred as a regulatory asset or liability. The deferred amount is either billed or refunded to customers in a subsequent period. RESRAM regulatory assets earn carrying costs at short-term interest rates. The RESRAM permits Ameren Missouri to recover investments in wind generation and other renewables related to compliance with Missouri’s renewable energy standard, and earn a return at the applicable WACC on those investments not already provided for in customer rates or any other recovery mechanism, such as the renewable energy standard cost tracker. The renewable energy standard cost tracker allows Ameren Missouri to defer differences between actual costs primarily associated with the Maryland Heights Energy Center and renewable energy credits obtained through a 102-MW power purchase agreement with a wind farm operator, which expires in 2024, and those costs included in customer rates.

The FAC permits Ameren Missouri to recover or refund, through customer rates, 95% of the variance in net energy costs from the amount set in base rates without a traditional regulatory rate review, subject to MoPSC prudence reviews, with the remaining 5% of changes retained by Ameren Missouri. As such, Ameren Missouri’s results of operations are affected by the 5% not recovered or refunded under the FAC. The 95% variance in net energy costs in a given period is deferred as a regulatory asset or liability, and either billed or refunded to customers in a subsequent period. FAC regulatory assets earn carrying costs at short-term interest rates. Ameren Missouri’s base rates for electric service are required to be reset at least every four years to allow for continued use of the FAC.

The MEEIA permits Ameren Missouri to recover customer energy-efficiency program costs, the related lost electric margins, and any performance incentive through the MEEIA without a traditional regulatory rate review, subject to MoPSC prudence reviews. MEEIA assets earn carrying costs at short-term interest rates.

Ameren Missouri is a member of the MISO, and its transmission rate is calculated in accordance with the MISO Open Access Transmission, Energy, and Operating Reserve Markets Tariff. The FERC regulates the rates charged and the terms and conditions for wholesale electric transmission service. The transmission rate update each June is based on Ameren Missouri’s actual historical cost from the prior calendar year. This rate is not directly charged to Missouri retail customers because, in Missouri, the revenue requirement used to set bundled retail base rates includes an amount for transmission-related costs and revenues.

The PGA allows Ameren Missouri to recover costs of natural gas purchased on behalf of its customers without a traditional regulatory rate review, subject to MoPSC prudence reviews. These pass-through purchased gas costs do not affect Ameren Missouri’s natural gas margins, as any change in costs is offset by a corresponding change in revenues. The difference between actual natural gas costs and costs billed to customers in a given period is deferred as a regulatory asset or liability. The deferred amount is either billed or refunded to customers in a subsequent period. PGA regulatory assets earn carrying costs at short-term interest rates. The WNAR allows Ameren Missouri to adjust natural gas delivery service rates charged to residential customers without a traditional regulatory rate review, subject to MoPSC prudence reviews, when deviations from normal weather conditions cause natural gas revenues to vary from the related revenue requirement approved by the MoPSC in the previous regulatory rate review. The impact of deviations from normal weather on natural gas delivery service revenues billed to residential customers in a given period are deferred as a regulatory asset or liability. WNAR regulatory assets earn carrying costs at short-term interest rates. The deferred amount is either billed or refunded to residential customers in a subsequent period. The WNAR was approved by a December 2021 MoPSC natural gas rate order and became effective ~~on April 1, 2017.~~February 28, 2022, replacing a rate-adjustment mechanism that had decoupled natural gas revenues from actual sales volumes.

The ICC regulates rates and other matters for Ameren Illinois’ electric distribution service and natural gas distribution businesses. The rates Ameren Illinois charges customers for electric distribution service are calculated under a performance-based formula ratemaking framework pursuant to the IEIMA. Pursuant to the IETL and December 2022 and March 2021 ICC orders, Ameren Illinois used the IEIMA formula framework to establish annual customer rates effective through 2023 and filed an MYRP in January 2023 for rates that will become effective beginning in 2024. The orders also allow Ameren Illinois to reconcile its revenue requirement for customer rates established for 2022 and 2023. Pursuant to the orders, Ameren Illinois’ 2022 revenues reflected, and its 2023 revenues will reflect, each year’s actual recoverable costs, year-end rate base, and a return at the applicable WACC, with the ROE component based on the annual average of the monthly yields of the 30-year United States Treasury bonds plus 580 basis points. The revenue requirement reconciliation adjustment would be collected from, or refunded to, customers within two years from the end of the reconciled year. By law, the decoupling provisions extend beyond the end of existing performance-based formula ratemaking, which ensures that Ameren Illinois’ electric distribution revenues authorized in a regulatory rate review are not affected by changes in sales volumes. See below for additional information regarding the MYRP filed in January 2023. The rates Ameren Illinois charges customers for natural gas distribution service are established in a traditional regulatory rate review, which takes up to 11 months to complete, based on a future test year and the revenue requirement established in the review.

Ameren Illinois’ election to use the electric distribution service performance-based formula ratemaking framework allowed by state law, described below, permits Ameren Illinois to adjust customer rates to recover the cost of electric distribution service on an annual basis. Ameren Illinois’ electric distribution service also has other cost recovery mechanisms in place that allow customer rates to be adjusted without a traditional regulatory rate review. Ameren Illinois’ electric distribution service business has riders for power procurement and transmission services incurred on behalf of its customers, renewable energy credit compliance, zero emission credits, and certain environmental costs, as well as bad debt write-offs and the costs of certain asbestos-related claims not recovered in base rates. These pass-through costs do not affect Ameren Illinois’ net income, as any change in costs is offset by a corresponding change in revenues. Ameren Illinois’ cost recovery under any of its recovery mechanisms is subject to ICC prudence reviews.

Ameren Illinois’ electric distribution service performance-based formula ratemaking framework under the IEIMA allows Ameren Illinois to reconcile electric distribution service rates to its actual revenue requirement on an annual basis. If a given year’s revenue requirement varies from the amount collected from customers, an adjustment is made to electric operating revenues with an offset to a regulatory asset or liability to reflect that year’s actual revenue requirement, independent of actual sales volumes. The regulatory balance is then collected from, or refunded to, customers within two years from the end of the year. In addition, Ameren Illinois’ electric customer energy-efficiency rider provides Ameren Illinois’ electric distribution service business with recovery of, and return on, energy-efficiency investments. Under formula ratemaking for both its electric distribution service and its electric energy-efficiency investments, the revenue requirements are based on recoverable costs, year-end rate base, and a year-end ratemaking capital structure, and earn a return at the applicable WACC. The ROE component of the applicable WACC is based on the annual average of the monthly yields of the 30-year United States Treasury bonds plus 580 basis points and any performance-related basis point adjustments, described in more detail below. Therefore, Ameren Illinois’ annual ROE for its electric distribution business is directly correlated to the yields on such bonds. In addition, regulatory assets applicable to formula ratemaking for both electric distribution service and electric energy-efficiency investments earn a return at the applicable WACC. However, Ameren Illinois recognizes the cost of debt on these regulatory assets in revenue, instead of the applicable WACC, with the difference recognized in revenues when recovery of such regulatory assets is reflected in customer rates. As discussed above, Ameren Illinois filed an MYRP to establish electric distribution service rates beginning in 2024. Ameren Illinois will continue to use formula ratemaking to establish annual customer rates related to its electric energy-efficiency investments beyond 2023.

Ameren Illinois’ electric distribution service business is also subject to performance standards. Failure to achieve the standards would result in a reduction in the company’s allowed ROE calculated under the formula ratemaking recovery mechanism. The performance standards applicable to electric distribution service under the IEIMA include improvements in service reliability to reduce both the frequency and duration of outages, a reduction in the number of estimated bills, a reduction of consumption from inactive meters, and a reduction in bad debt expense. The 2023 allowed ROE for electric distribution service is subject to the performance standards related to reduced estimated bills and bad debt expense, and may be decreased for penalties up to 10 basis points if these performance standards are not met. The allowed ROE on energy-efficiency investments can be increased or decreased up to 200 basis points, depending on the achievement of annual energy savings goals. Any adjustments to the allowed ROE for energy-efficiency investments will depend on annual performance for a historical period relative to energy savings goals. In 2022, 2021, and 2020, there were no performance-related basis point adjustments that materially affected financial results.

Ameren Illinois’ natural gas distribution business has recovery mechanisms, including the QIP, PGA, and VBA, that allow customer rates to be adjusted without a traditional regulatory rate review. These riders, described in more detail below, mitigate the effects of regulatory lag. Ameren Illinois employs other riders for natural gas customer energy-efficiency program costs and certain environmental costs, as well as bad debt write-offs and invested capital taxes not recovered in base rates. Pass-through costs under the riders do not affect Ameren Illinois’ net income, as any change in costs is offset by a corresponding change in revenues. Ameren Illinois’ cost recovery under any of its recovery

The QIP provides Ameren Illinois with recovery of, and a return on, qualifying natural gas infrastructure investments that are placed in service between regulatory rate reviews. Infrastructure investments under the QIP earn a return at the applicable WACC. Eligible natural gas investments include projects to improve safety and reliability and modernization investments, such as smart meters. The deferrals are recorded as a regulatory asset, with recovery beginning two months after the qualifying natural gas plant is placed in service and continuing until such plant is included in base rates in a natural gas delivery service rate order. Ameren Illinois’ QIP is subject to a rate impact limitation of a cumulative 4% per year since the most recent delivery service rate order, ~~authorized~~with no single year exceeding 5.5%. If the rate impact limitation was met in a particular year, the amount of rate base causing the QIP rate to exceed the limitation would be exposed to regulatory lag until a year when that amount could be recovered under QIP or is added to rate base as a part of a regulatory rate review. Upon issuance of a natural gas delivery service rate order, QIP rate base is transferred to base rates and the QIP is reset to zero, which mitigates the risk that the QIP will exceed its statutory limitations in future years and ensures timely recovery of capital investments. Without legislative action, the QIP will expire after December 2023.

The PGA allows Ameren Illinois to recover costs of natural gas purchased on behalf of its customers without a traditional regulatory rate review, subject to ICC prudence reviews. These pass-through purchased gas costs do not affect Ameren Illinois natural gas margins, as any change in costs is offset by a corresponding change in revenues. The difference between actual natural gas costs and costs billed to customers in a given period is deferred as a regulatory asset or liability. The deferred amount is either billed or refunded to customers in a subsequent period. PGA regulatory assets earn carrying costs at short-term interest rates. The VBA ensures recoverability of the natural gas distribution service revenue requirement that is dependent on sales volumes for residential and small nonresidential customers. For these rate classes, the VBA allows Ameren Illinois to adjust natural gas distribution service rates without a traditional regulatory rate review when changes occur in sales volumes from those volumes approved by the ICC in a previous regulatory rate review. The difference between allowed sales revenues and amounts billed to customers in a given period is deferred as a regulatory asset or liability. The deferred amount is collected from, or refunded to, customers in a subsequent period. VBA regulatory assets for a given year that are not fully collected by the end of the following year begin earning carrying costs at short-term interest rates.

The FERC regulates rates and other matters for Ameren Illinois’ transmission business and ATXI, as well as for Ameren Missouri. See the discussion above related to Ameren Missouri. Both Ameren Illinois and ATXI are members of the MISO, and their transmission rates are calculated in accordance with the MISO Open Access Transmission, Energy, and Operating Reserve Markets Tariff. Ameren Illinois and ATXI have received FERC approval to use a company-specific, forward-looking formula ratemaking framework in setting their transmission rates. These forward-looking rates are updated annually and become effective each January with forecasted information. The formula rate framework provides for an annual reconciliation of the electric transmission service revenue requirement, which reflects the actual recoverable costs incurred and the 13-month average rate base for a given year, with the revenue requirement in customer rates, including an allowed ROE. If a given year’s revenue requirement varies from the amount collected from customers, an adjustment is made to electric operating revenues with an offset to a regulatory asset or liability to reflect that year’s actual revenue requirement, independent of actual sales volumes. The regulatory balance is collected from, or refunded to, customers within two years from the end of the year. FERC revenue requirement reconciliation adjustment regulatory assets earn carrying costs at each company’s short-term interest rates. In addition, the FERC has approved transmission rate incentives, including a 50 basis point incentive adder to the allowed base ROE for Ameren Illinois and ATXI for participation in an RTO.

In August 2022, Ameren Missouri filed a request with the MoPSC seeking approval to increase its annual revenues for electric service by $316 million. The electric rate increase request is based on a 10.2% ROE, a capital structure composed of 51.93% common equity, a rate base of $11.6 billion, and a test year ended March 31, 2022, with certain pro-forma adjustments expected through an anticipated true-up date of December 31, 2022. Ameren Missouri’s request includes the continued use of the FAC and ~~the regulatory tracking mechanisms~~trackers for pension and postretirement benefits, uncertain income tax positions, certain excess deferred income taxes, and renewable energy ~~standards~~standard costs that the MoPSC previously authorized in earlier electric rate ~~orders. These~~orders, as well as the use of an electric property tax tracker allowed under Missouri Senate Bill 745 discussed below. In October 2022, Ameren Missouri also requested the use of a tracker for variances between actual income tax benefits and costs resulting from the IRA and those amounts included in customer rates, which would be considered for recovery or refund in a future electric regulatory rate review. For additional information regarding the IRA, see Note 12 – Income Taxes. The electric rate increase request reflects the following:

In connection with the planned accelerated retirement of the Rush Island Energy Center, Ameren Missouri expects to seek approval from the MoPSC to finance the costs associated with the retirement, including the remaining unrecovered net plant balance associated with the facility, through the issuance of securitized utility tariff bonds pursuant to the Missouri securitization statute. As such, Ameren Missouri did not request a change in the depreciation rates related to the Rush Island Energy Center in this electric service regulatory rate review.

In January 2023, the MoPSC staff recommended an increase to Ameren Missouri's annual electric service revenues of $199 million based on a 9.59% ROE, a capital structure composed of 51.84% common equity, and a rate base as of June 30, 2022, of $10.5 billion. Ameren Missouri expects the MoPSC staff will update its rate base estimate through the anticipated true-up date of December 31, 2022. The MoPSC staff’s recommendation of $199 million includes an adjustment to annual electric service revenues of $128 million for estimated true-up items from June 30, 2022, to December 31, 2022, including the impacts of any investments made during that period. Their recommendation also includes adjustments for lower off-system sales revenue, production tax credits, and renewable energy credits as a result of the curtailed nighttime operations at the High Prairie Energy Center to limit its impact on protected species, and a lower rate base for the Rush Island Energy Center due to its reduced operation in compliance with a system support resource agreement approved by the FERC in October 2022, among other things. See Note 14 – Commitments and Contingencies for additional information on the curtailed nighttime operations at the High Prairie Energy Center and the Rush Island Energy Center system support resource agreement. The MoPSC staff supported the authorization of a tracker for future production tax credits and proceeds from the sale of tax credits allowed under the IRA, but did not recommend tracking ~~mechanisms provide for a base level~~investment tax credits or costs resulting from the IRA, including the 15% minimum tax on adjusted financial statement income imposed by the law. The MoPSC staff also recommended that deferrals under the electric property tax tracker discussed below should begin on the effective date of ~~expense to be reflected~~new rates established by this proceeding, rather than the effective date of the enactment of Missouri Senate Bill 745.

In January 2023, the MoOPC challenged approximately 29% of the costs and requested return associated with the High Prairie Energy Center investment included in Ameren Missouri’s ~~base~~requested revenue requirement as a result of the curtailed nighttime operations at the energy center discussed above.

The MoPSC proceeding relating to the proposed electric service rate changes will take place over a period of up to 11 months, with a decision by the MoPSC expected by June 2023 and new rates ~~with differences~~effective by July 2023. Ameren Missouri cannot predict the level of any electric service rate change the MoPSC may approve, whether the requested regulatory recovery mechanisms will be approved, or whether any rate change that may eventually be approved will be sufficient for Ameren Missouri to recover its costs and earn a reasonable return on its investments when the rate change goes into effect.

Missouri Senate Bill 745 became effective on August 28, 2022. The law extended Ameren Missouri’s PISA election through December 2028 and allows for an additional extension through December 2033 if requested by Ameren Missouri and approved by the MoPSC, among other things. The law established a 2.5% annual limit on increases to the electric service revenue requirement used to set customer rates due to the inclusion of incremental PISA deferrals in the revenue requirement. The limitation will be effective for revenue requirements approved by the MoPSC after January 1, 2024, and will be based on the revenue requirement established in the immediately preceding rate order. The law also established electric and natural gas property tax trackers that allow Ameren Missouri to defer the difference between ~~the base amount~~actual property taxes incurred and ~~the actual expenses incurred deferred~~related taxes included in customer rates as a regulatory asset or ~~liability. Excluding cost reductions associated~~regulatory liability, with ~~reduced sales volumes,~~ the difference expected to be reflected in rate base ~~level of net energy costs decreased by $54 million from the base level established~~ in ~~the MoPSC’s April 2015 electric~~a subsequent rate order. ~~Changes~~Upon the effective date of the law, Ameren Missouri began deferring amounts under these trackers. The deferrals were immaterial as of December 31, 2022.

In July 2022, Ameren Missouri filed a request with the MoPSC seeking approval of its Renewable Solutions Program and a tariff related to participation in the program. The program would allow certain commercial, industrial, and governmental customers to receive up to 100% of their energy from renewable resources. Based on customer contracts, the program would enable Ameren Missouri to supply renewable solar energy generated by the Boomtown Solar Project discussed above to customers that enroll in the program. Ameren Missouri expects a decision from the MoPSC by April 2023.

In February 2022, the MoPSC issued an ~~appeal~~order directing the MoPSC staff to review Ameren Missouri’s planned accelerated retirement of the ~~order~~Rush Island Energy Center as a result of the NSR and Clean Air Act Litigation discussed in Note 14 – Commitments and Contingencies. The MoPSC staff’s review includes potential impacts on the reliability and cost of Ameren Missouri’s service to its customers; Ameren Missouri’s plans to mitigate the customer impacts of the accelerated retirement; and the prudence of Ameren Missouri’s actions and decisions with regard to the Rush Island Energy Center, among other things. In April 2022, the MoPSC staff filed an initial report with the ~~Missouri Court~~MoPSC in which the staff concluded early retirement of ~~Appeals, Western District. In December 2016,~~ the ~~Missouri Court of Appeals, Western District, upheld the November 2015~~Rush Island Energy Center may cause reliability concerns. The MoPSC ~~order.~~staff is under no deadline to complete this review. Ameren Missouri ~~then appealed that decision~~is unable to predict the ~~Missouri Supreme Court. If the decision is overturned, Ameren Missouri would recognize an additional $9 million MEEIA 2013 performance incentive.~~

In August 2022, the ~~potential to earn more if Ameren Missouri’s energy savings exceeded those goals. In September 2017, Ameren Missouri received~~MoPSC issued an order ~~from the MoPSC~~ approving Ameren Missouri’s energy savings results for the ~~first~~2021 program year of the MEEIA ~~2016 programs.~~2019 program. In December 2022, Ameren Missouri achieved certain energy-efficiency spending goals for the 2022 program year of the MEEIA 2019 program. As a result of this order, achieving the spending goals for the 2022 program year, and MoPSC orders issued in ~~accordance with revenue recognition guidance,~~September 2021 and August 2020, Ameren Missouri ~~will recognize $5~~recognized revenues of $22 million, ~~of additional revenues~~$9 million, and $6 million in ~~the first quarter of 2018 relating to the MEEIA 2016 performance incentive.~~2022, 2021, and 2020, respectively.

In ~~February 2018,~~December 2021, the MoPSC ~~initiated proceedings to investigate how the effect of the reduction~~issued orders in ~~the federal statutory corporate income tax rate enacted under the TCJA should be reflected in rates paid by customers of~~Ameren Missouri’s ~~regulated utilities, including rates paid by~~2021 electric service and natural gas ~~customers of Ameren Missouri. At this time, Ameren Missouri is unable to predict the timing or the magnitude of any impact on its~~delivery service regulatory rate reviews. The new electric and natural gas rates ~~that may result from the ultimate resolution of this matter.~~

The ~~Mark Twain project~~electric order resulted in an increase of $220 million to Ameren Missouri’s annual revenue requirement for electric retail service. The approved revenue requirement is based on a ~~MISO-approved transmission line to be located~~rate base of $10.2 billion, infrastructure investments as of September 30, 2021, and a change in ~~northeast Missouri with an expected investment~~the depreciable lives of ~~$250 million. In~~ the ~~third quarter of 2017, ATXI finalized an alternative project route~~Sioux and ~~reached agreements~~Rush Island energy centers’ assets consistent with Ameren ~~Missouri and~~Missouri’s 2020 IRP. The order did not specify an ~~electric cooperative in northeast Missouri to locate almost all~~ROE, but specified that Ameren Missouri’s September 30, 2021 capital structure, which was composed of the Mark Twain project on existing line corridors. It also received assents for road crossings from the five affected counties in northeast Missouri. In January 2018, the MoPSC granted ATXI a certificate of convenience and necessity for the Mark Twain project. ATXI plans to begin construction51.97% common equity, will be used in the ~~second quarter~~PISA and RESRAM. The order changed annualized depreciation, regulatory asset and liability amortization amounts, and the base level of ~~2018~~expenses for trackers. On an annualized basis, these changes reflect approximate increases in depreciation and amortization of $140 million and other operating and maintenance expenses of $40 million.

The natural gas order resulted in an increase of $5 million to ~~complete the project by the end~~Ameren Missouri’s annual revenue requirement for natural gas delivery service. The approved revenue requirement is based on a rate base of ~~2019.~~$313 million and infrastructure investments as of September 30, 2021. The order did not specify an ROE or a capital structure.

~~Under a formula ratemaking framework effective through 2022,~~In January 2023, Ameren ~~Illinois’~~Illinois filed an MYRP with the ICC to be used in setting electric distribution service rates for 2024 through 2027. Under the MYRP, the ICC would approve base rates for electric distribution service to be charged to customers for each calendar year of the four-year period. The following table includes the forecasted revenue requirement, the requested ROE, the requested capital structure common equity percentage, and the forecasted average annual rate base for 2024 through 2027, as reflected in Ameren Illinois’ MYRP:

Under an MYRP, the IETL permits any initial rate increase to be phased in, with at least 50% of the first annual period’s approved rate increase reflected in rates in the first annual period, with the remaining portion deferred as a regulatory asset that earns a return at the applicable WACC and is collected from customers over a period not to exceed two years beginning within one year after the second annual period’s rates are effective. Ameren Illinois’ MYRP filing utilizes this phase-in provision and proposes to defer 50% of the requested 2024 rate increase of $175 million as a regulatory asset to be collected from customers in 2026. Ameren Illinois recognizes revenues when amounts are expected to be collected from customers within two years from the end of an applicable year. An ICC decision in this proceeding is required by December 2023, with new rates effective starting in January 2024. Ameren Illinois cannot predict the level of any electric distribution service rate change the ICC may approve, or whether any rate change that may eventually be approved will be sufficient for Ameren Illinois to recover its costs to the extent those costs are subject to and exceed the reconciliation cap discussed below and earn a reasonable return on its investments when the rate change goes into effect.

The MYRP also allows Ameren Illinois to reconcile its actual revenue requirement, as adjusted for certain cost variations, to ICC-approved electric distribution service rates on an annual basis, subject to a reconciliation cap. The reconciliation cap limits the annual adjustment to 105% of the annual revenue requirement approved by the ICC. Certain variations from forecasted costs would be excluded from the reconciliation ~~to its actual recoverable~~cap, including those associated with major storms; new business and facility relocations; changes in the timing of certain expenditures or investments into or out of the applicable calendar year; and changes in interest rates, income taxes, taxes other than income taxes, pension and other post-retirement benefits costs, and ~~allowed return on equity.~~amortization of certain assets. The ~~formula ratemaking framework qualifies~~reconciliation cap also excludes costs recovered through riders outside of base rates, such as riders for electric energy-efficiency investments, power procurement and transmission services, renewable energy credit compliance, zero emission credits, certain environmental costs, and bad debt write-offs, among others. Ameren Illinois’ existing riders will remain effective and electric distribution service revenues will continue to be decoupled from sales volumes under the MYRP. The actual revenue requirement for a particular year would incorporate Ameren Illinois’ year-end rate base and actual capital structure for such year, provided that the common equity ratio in such capital structure may not exceed that approved by the ICC in the MYRP. Excluding the phase-in of the initial rate increase discussed above, and subject to the reconciliation cap, if a given year’s revenue amount collected from customers varies from the approved revenue requirement, an ~~alternative revenue program under GAAP. Each year, Ameren Illinois records~~adjustment would be made to electric operating revenues with an offset to a regulatory asset or ~~a regulatory~~ liability ~~and a corresponding increase or decrease~~ to ~~operating revenues for any differences between the~~reflect that year’s actual revenue requirement, ~~reflected in customer rates for that year and its estimate~~independent of actual sales volumes. The regulatory balance would then be collected from, or refunded to, customers within two years from the end of the ~~probable increase or decrease in~~applicable annual period.

In December ~~2017,~~2022, the ICC issued an order in Ameren Illinois’ annual update filing that approved a ~~$17~~$61 million ~~decrease~~increase in Ameren Illinois’ electric ~~delivery~~distribution service ~~revenue requirement~~rates beginning in January ~~2018.~~2023. This ~~update~~order reflected an increase to the annual performance-based formula rate based on ~~2016~~2021 actual recoverable costs and expected net plant additions for ~~2017, as well as~~2022, an increase to include the ~~2016~~2021 revenue requirement reconciliation ~~adjustment. The increases in the update filing were more than offset by~~adjustment including a capital structure composed of 50% common equity, and a decrease for the conclusion of the ~~2015~~2020 revenue requirement reconciliation adjustment, which was fully collected from customers in ~~2017,~~2022, consistent with the ICC’s December ~~2016~~2021 annual update filing order.

In December 2022, the ~~IEIMA, including extending the IEIMA formula ratemaking framework through 2022, and clarifying that a common equity ratio up to and including 50% is prudent. Beginning~~ICC issued an order in 2017, the FEJA permitted Ameren Illinois to recover, within the following two years, its electric distribution revenue requirement for a given year, independent of actual sales volumes. Prior to the FEJA, Ameren Illinois’ ~~interim period revenue recognition was volume-based, as revenues were affected by the timing~~annual update filing that approved electric customer energy-efficiency rates of ~~sales volumes due to seasonal rates and changes~~$76 million beginning in ~~volumes resulting~~January 2023, which represents an increase of $15 million from among other things, weather and energy efficiency. This previous revenue recognition method resulted in more revenue during the third quarter and less revenue during the other quarters of each year. Beginning in 2017, in connection with the decoupling provisions of the FEJA, Ameren Illinois changed the method it uses to recognize interim-period revenue. Ameren Illinois now recognizes revenue consistent with the timing of actual incurred electric distribution recoverable costs, and it recognizes revenue associated with the expected return on its rate base ratably over the year. The decoupling provisions of the FEJA do not expire at the end of 2022.2022 rates.

The FEJA allows Ameren Illinois to earn a return on its electric energy-efficiency program investments. Ameren Illinois’ electric energy-efficiency investments are deferred as a regulatory asset and earn a return at the company’s weighted-average cost of capital, with the equity return based on the monthly average yield of the 30-year United States Treasury bonds plus 580 basis points. The equity portion of Ameren Illinois’ return on electric energy-efficiency investments can be increased or decreased by up to 200 basis points, depending on the achievement of annual energy savings goals. The FEJA increased the level of electric energy-efficiency saving targets through 2030. In June ~~2017, pursuant to the FEJA, Ameren Illinois filed with the ICC an energy-efficiency plan for 2018 through 2021. In September 2017,~~2022, the ICC issued an order approving Ameren Illinois’ ~~implementation of the FEJA electric~~revised energy-efficiency ~~savings targets and investments. Ameren Illinois plans to invest up to $99 million per year in electric energy-efficiency programs from 2018 through 2021. Ameren Illinois plans to make similar yearly~~plan that includes annual investments in electric energy-efficiency programs ~~from 2022~~of approximately $120 million per year through ~~2030.~~2025, which reflects the increased level of annual investments allowed under the IETL. The ICC has the ability to reduce the amount of electric energy-efficiency savings goals in future program years if there are insufficient cost-effective programs available, ~~or if~~which could reduce the ~~savings goals would require investment levels that exceed amounts allowed by legislation.~~investments in electric energy-efficiency programs. The electric energy-efficiency program investments and the return on those investments ~~will be~~are collected from customers through a ~~rider; they will~~rider and are not ~~be included in~~recovered through the ~~IEIMA~~electric distribution service performance-based formula ratemaking framework.

In January ~~2018,~~2023, Ameren Illinois filed a request with the ICC seeking approval to increase its annual revenues for natural gas delivery service by ~~$49~~$160 million, which included an estimated ~~$42~~$77 million of annual revenues that would otherwise be recovered under athe QIP ~~rider~~. and other riders. The request ~~was~~is based on a ~~10.3% return on common equity,~~10.7% allowed ROE, a capital structure composed of ~~50%~~53.99% common equity, and a rate base of ~~$1.6~~$2.9 billion. The request reflects the reduction in the federal corporate income tax rate as a result of the TCJA, as well as the increase in the Illinois corporate income tax rate that became effective in July 2017. In an attempt to reduce regulatory lag, Ameren Illinois used a ~~2019~~2024 future test year in this proceeding.

The IETL contains other provisions in addition to the ratemaking impacts discussed in the MYRP section above. The law permits Ameren Illinois to invest up to $20 million in each of two solar generation and battery storage pilot projects in Illinois. The first of these projects was placed in service in December 2022. Additionally, the law increased the existing customer surcharge for renewable energy resources, which funds IPA renewable energy credit procurement events. As a result, Ameren Illinois began collecting additional annual revenues of approximately $100 million, beginning in February 2022, under the rider for the procurement of renewable energy credits. It also established an Energy Transition Assistance Fund to support economic and workforce development programs designed to assist the state of Illinois with its transition to clean energy sources. The fund is subsidized through customer surcharges collected by electric utilities operating in the state, including Ameren Illinois, and is remitted in the month following collection to an Illinois state agency, with no impact to results of operations. In ~~August 2017,~~May 2022, Illinois Senate Bill 3866 was enacted and became effective. This legislation makes certain amendments to the IETL, including amendments to increase the allowed level of funding for the Energy Transition Assistance Fund. Ameren Illinois ~~Circuit Court for Edgar County dismissed several of ATXI’s condemnation cases~~expects to collect approximately $25 million annually related to ~~one line segment~~this fund, beginning in January 2023, which could be increased to up to $50 million in future years. Pursuant to the IETL, Ameren Illinois is required to file a multi-year integrated grid plan with the ICC every four years. In January 2023, Ameren Illinois filed its first multi-year integrated grid plan for the years 2023 to 2027. The plan outlines how Ameren Illinois expects to operate and invest in electric distribution infrastructure in order to support grid modernization, clean energy, energy efficiency, and the state of Illinois’ renewable energy, equity, climate, electrification, and environmental goals, while providing safe, secure, reliable, and resilient electric distribution service to customers. Ameren Illinois’ next multi-year integrated grid plan is required by mid-January 2026.

In December 2022, the ICC issued an order approving Ameren Illinois’ QIP reconciliation for 2019. The 10.82% total allowed return on common equity has been reflected in rates since September 2016. The 10.82% allowed return on common equity may be replaced prospectively after the FERC issues a final order in the February 2015 complaint case, discussed below.

In ~~June 2016, an administrative law judge issued an initial decision in the~~ February 2015 complaint case. If approved by the FERC, it would lower the allowed base return on common equity for the 15-month period of February 2015 to May 2016 to 9.70%, or a 10.20% total allowed return on equity with the inclusion of a 50 basis point incentive adder for participation in an RTO. It would also require customer refunds, with interest, for that 15-month period. A final FERC order would also establish the allowed return on common equity that will apply prospectively from the effective date of such order, replacing the current 10.82% total return on common equity.The timing of the issuance of the final order in the February 2015 complaint case is uncertain for two reasons. First, while the FERC reestablished a quorum of commissioners in August 2017 after six months without a quorum, the FERC is under no deadline to issue a final order. Second, in the second quarter of 2017, the United States Court of Appeals for the District of

Since November 2013, the allowed base ROE for FERC-regulated transmission rate base under the MISO tariff has been subject to customer complaint cases and has been changed by various FERC orders. In May 2020, the FERC issued an order, which set the allowed base ROE to 10.02%, and required refunds, with interest, for the periods November 2013 to February 2015 and from late September 2016 forward. Ameren and Ameren Illinois paid these refunds, including interest, by March 31, 2022. In June and July 2020, Ameren Missouri, Ameren Illinois, and ATXI, as ~~discussed above.~~well as various customers, petitioned the United States Court of Appeals for the District of Columbia Circuit for review of the May 2020 order, challenging certain aspects of the new ROE methodology established. The petition filed by Ameren Missouri, Ameren Illinois, and ATXI challenged the refunds required for the period from September 2016 to May 2020. In August 2022, the court issued a ruling that granted the customers’ petition for review, vacated the FERC’s previous MISO ROE-determining orders, and remanded the proceedings to the FERC. The court did not rule on the petition filed by Ameren Missouri, Ameren Illinois, and ATXI. The currently allowed base ROE of 10.02% will remain effective for customer billings, but subject to refund if the base ROE is changed by the FERC in a future order. The FERC is under no deadline to issue an order ~~on this motion.~~

In accordance with authoritative accounting guidance regarding accounting for the effects of certain types of regulation, we defer certain costs as regulatory assets pursuant to actions of regulators or because we expect to recover such costs in rates charged to customers. We may also defer certain amounts as regulatory liabilities because of actions of regulators or because we expect that such amounts will be returned to customers in future rates. The following table presents our regulatory assets and regulatory liabilities at December 31, ~~2017~~2022 and ~~2016:~~2021:

The following table presents components of “Property, plant, and equipment, net” at December 31, 2022 and 2021:

Capitalized software costs are classified within “Property, Plant, and Equipment, Net” on the balance sheet and are amortized on a straight-line basis over the expected period of benefit, ranging from 52 to 1015 years. The following table presents the amortization, gross carrying value, ~~of capitalized software, the~~and related accumulated amortization ~~and the amortization expense~~ of capitalized software by year:

Amortization Expense^(a)
Gross Carrying Value Accumulated Amortization
2017 2016 2015 2017 2016 2017 2016
Ameren $ 58
$ 52
$ 47
$ 655
$ 622
$ (466 ) $ (408 )
Ameren Missouri 20
17
16
191
178
(107 ) (87 )
Ameren Illinois 36
33
27
241
225
(146 ) (110 )

The liquidity needs of the Ameren Companies are typically supported through the use of available cash, drawings under committed credit agreements, commercial paper issuances, and/or, in the case of Ameren Missouri and Ameren Illinois, short-term affiliate borrowings.

In December 2022, the Credit Agreements,

The borrowers have the option to seek additional commitments from existing or new lenders to increase the total facility size of the Credit Agreements to a maximum of ~~$1.2~~$1.7 billion for the Missouri Credit Agreement and ~~$1.3~~$1.5 billion for the Illinois Credit Agreement. Ameren (parent) borrowings are due and payable no later than the maturity date of the Credit Agreements. Ameren Missouri and Ameren Illinois borrowings under the applicable Credit Agreement are due and payable no later than the earlier of the maturity date or 364 days after the ~~originating~~ date of the borrowing.

The obligations of the borrowers under the Credit Agreements are unsecured. Loans are available on a revolving basis under each of the Credit Agreements. Funds borrowed may be repaid and, subject to satisfaction of the conditions to borrowing, reborrowed from time to time. At the election of each borrower, the interest rates on such loans will be the alternate base rate plus the margin applicable to the particular borrower and/or the eurodollar rate plus the margin applicable to the particular borrower. The applicable margins will be determined by the borrower’s long-term unsecured credit ratings or, if no such ratings are in effect, the borrower’s corporate/issuer ratings then in effect. The borrowers have received commitments from the lenders to issue letters of credit up to $100 million under each of the Credit Agreements. In addition, the issuance of letters of credit is subject to the ~~$2.1~~$2.6 billion overall combined facility borrowing limitations of the Credit Agreements.

The borrowers will use the proceeds from any borrowings under the Credit Agreements for general corporate purposes, including working capital, commercial paper liquidity support, ~~issuance of letters of credit,~~ loan funding under the Ameren money pool arrangements, and other short-term affiliate

~~Ameren, Ameren Missouri, and Ameren Illinois did not borrow under the Credit Agreements for the years ended December 31, 2017 and 2016.~~

The information below is a summary of the Ameren Companies’ compliance with indebtedness provisions and other covenants.

The Credit Agreements contain conditions for borrowings and issuances of letters of credit. These conditions include the absence of default or unmatured default, material accuracy of representations and warranties (excluding any representation after the closing date as to the absence of material adverse change and material litigation, and the absence of any notice of violation, liability, or requirement under any environmental laws that could have a material adverse effect), and obtaining required regulatory authorizations. In addition, it is a condition for any Ameren Illinois borrowing that, at the time of and after giving effect to such borrowing, Ameren Illinois not be in violation of any limitation on its ability to incur unsecured indebtedness contained in its articles of incorporation.

The Credit Agreements also contain nonfinancial covenants, including restrictions on the ability to incur certain liens, to transact with affiliates, to dispose of assets, to make investments in or transfer assets to its affiliates, and to merge with other entities. The Credit Agreements require each of Ameren, Ameren Missouri, and Ameren Illinois to maintain consolidated indebtedness of not more than 65% of its consolidated total capitalization pursuant to a defined calculation set forth in the agreements. As of December 31, ~~2017,~~2022, the ratios of consolidated indebtedness to total consolidated capitalization, calculated in accordance with the provisions of the Credit Agreements, were ~~53%~~59%, ~~48%~~49%, and ~~47%~~46%, for Ameren, Ameren Missouri, and Ameren Illinois, respectively.

The Credit Agreements contain default provisions that apply separately to each borrower. However, a default of Ameren Missouri or Ameren Illinois under the applicable credit agreement is also deemed to constitute a default of Ameren (parent) under such agreement. Defaults include a cross-default resulting from a default of such borrower under any other agreement covering outstanding indebtedness of such borrower and certain subsidiaries (other than project finance subsidiaries and nonmaterial subsidiaries) in excess of $100 million in the aggregate (including under the other credit agreement). However, under the default provisions of the Credit Agreements, any default of Ameren (parent) under either credit agreement that results solely from a default of Ameren Missouri or Ameren Illinois does not result in a cross-default of Ameren (parent) under the other credit agreement. Further, the Credit Agreements default provisions provide that an Ameren (parent) default under either of the Credit Agreements does not constitute a default by Ameren Missouri or Ameren Illinois.

Ameren has money pool agreements with and among its subsidiaries to coordinate and provide for certain short-term cash and working capital requirements.

Ameren Missouri, Ameren Illinois, and ATXI may participate in the utility money pool as both lenders and borrowers. Ameren (parent) and Ameren Services may participate in the utility money pool only as lenders. Surplus internal funds are contributed to the money pool from participants. The primary sources of external funds for the utility money pool are the Credit Agreements and the commercial paper programs. The total amount available to the pool participants from the utility money pool at any given time is reduced by the amount of borrowings made by participants, but it is increased to the extent that the pool participants advance surplus funds to the utility money pool or remit funds from other external sources. The availability of funds is also determined by funding requirement limits established by regulatory authorizations. Participants receiving a loan under the utility money pool agreement must repay the principal amount of such loan, together with accrued interest. The rate of interest depends on the composition of internal and external funds in the utility money pool. The average interest rate for borrowing under the utility money pool for the year ended December 31, ~~2017,~~2022, was ~~1.19% (2016~~1.95% (2021 – ~~0.52%~~0.17%).

See Note 13 – Related-party Transactions for the amount of interest income and expense from the utility money pool ~~arrangements~~agreement recorded by ~~the~~ Ameren ~~Companies~~Missouri and Ameren Illinois for the years ended December 31, ~~2017, 2016,~~2022, 2021, and ~~2015.~~2020.

The following table presents long-term debt outstanding, including maturities due within one year, as of December 31, 2022 and 2021:

2017 2016
Ameren Illinois:
Bonds and notes:
6.125% Senior secured notes due 2017^(g)(h)
$ —
$ 250
6.25% Senior secured notes due 2018^(g)(h)
144
144
9.75% Senior secured notes due 2018^(g)(h)
313
313
2.70% Senior secured notes due 2022^(g)(h)
400
400
5.90% First mortgage bonds due 2023⁽ⁱ⁾
(i)
(i)
5.70% First mortgage bonds due 2024^(j)
(j)
(j)
3.25% Senior secured notes due 2025^(g)
300
300
6.125% Senior secured notes due 2028^(g)
60
60
1993 Series B-1 Senior unsecured notes due 2028^(d)(k)
17
17
6.70% Senior secured notes due 2036^(g)
61
61
6.70% Senior secured notes due 2036^(l)
42
42
4.80% Senior secured notes due 2043^(g)
280
280
4.30% Senior secured notes due 2044^(g)
250
250
4.15% Senior secured notes due 2046^(g)
490
490
3.70% First mortgage bonds due 2047^(m)
500
—
Total long-term debt, gross 2,857
2,607
Less: Unamortized discount and premium (3 ) —
Less: Unamortized debt issuance costs (24 ) (19 )
Less: Maturities due within one year (457 ) (250 )
Long-term debt, net $ 2,373
$ 2,338
ATXI:
3.43% Senior notes due 2050⁽ⁿ⁾
$ 450
$ —
Total long-term debt, gross 450
—
Less: Unamortized debt issuance costs (2 ) —
Long-term debt, net $ 448
$ —
Ameren consolidated long-term debt, net $ 7,094
$ 6,595

Ameren
(parent)^(a)

Ameren
Missouri^(a)

Ameren
Illinois^(a)

ATXI^(a)

Ameren
Consolidated
2018 $ —
$ 384
$ 457
$ —
$ 841
2019 —
581
—
—
581
2020 350
92
—
—
442
2021 —
8
—
—
8
2022 —
56
400
50
506
Thereafter 350
2,867
2,000
400
5,617
Total $ 700
$ 3,988
$ 2,857
$ 450
$ 7,995

Under the DRPlus and its 401(k) plan, Ameren issued 0.5 million, 0.5 million, and 0.7 million shares of common stock in 2022, 2021, and 2020, respectively, and received proceeds of $41 million, $47 million, and $51 million for the respective years, and had a receivable of $8 million as of December 31, 2022. In ~~December 2017,~~addition, Ameren issued 0.4 million, 0.5 million, and 0.5 million shares of common stock valued at $31 million, $33 million, and $38 million in 2022, 2021, 2020, respectively, for no cash consideration in connection with stock-based compensation.

In May 2020, Ameren filed a Form S-3 registration statement with the SEC, authorizing the offering of 4 million additional shares of its common stock under the DRPlus, which expires in May 2023. Shares of common stock sold under the DRPlus are, at Ameren’s option, newly issued shares, treasury shares, or shares purchased in the open market or in privately negotiated transactions.

In October 2020, Ameren, Ameren Missouri, and Ameren Illinois filed a Form S-3 shelf registration statement with the SEC, registering the issuance of an ~~indeterminate~~unspecified amount of certain types of securities. ~~The~~This registration statement ~~became effective immediately upon filing and~~ expires in ~~December 2020.~~October 2023.

Ameren filed a Form S-3 registration statement with the SEC in May 2017, authorizing the offering of 6 million additional shares of its common stock under DRPlus, which expires in 2020. Shares of common stock sold under DRPlus are, at Ameren’s option, newly issued shares, treasury shares, or shares purchased in the open market or in privately negotiated transactions. As of December 31, 2017 and 2016, DRPlus participant funds of $8 million were reflected on Ameren’s consolidated balance sheets in “Other current assets.”

In ~~June 2017,~~January 2023, Ameren ~~Missouri~~entered into a forward sale agreement under the ATM program relating to 0.2 million shares of common stock. The January 2023 forward sale agreement can be settled at Ameren’s discretion on or prior to October 3, 2024. The initial forward sale price was $89.31 for the January 2023 forward sale agreement.

In August 2019, Ameren entered into a forward sale agreement with a counterparty relating to 7.5 million shares of common stock. In December 2020, pursuant to the agreement terms, Ameren partially settled the forward sale agreement by physically delivering 5.9 million shares of common stock for cash proceeds of $425 million. In February 2021, Ameren settled the remainder of the forward sale agreement by physically delivering 1.6 million shares of common stock for cash proceeds of $113 million. The proceeds were used to fund a portion of Ameren Missouri’s wind generation investments. See Note 15 – Supplemental Information for additional information about the wind generation facilities.

In March 2021, Ameren (parent) issued ~~$400~~$450 million of ~~2.95%~~1.75% senior ~~secured~~unsecured notes due ~~June~~March 2028, with interest payable semiannually on March 15 and September 15 of each year, beginning September 15, 2021. Ameren received net proceeds of $447 million which were used for general corporate purposes, including the repayment of short-term debt.

In November 2021, Ameren (parent) issued $500 million of 1.95% senior unsecured notes due March 2027, with interest payable semiannually on ~~June~~March 15 and ~~December~~September 15 of each year, beginning ~~December~~March 15, ~~2017.~~2022. Ameren ~~Missouri~~ received net proceeds of ~~$396~~$497 million which were used ~~in conjunction with other available funds,~~ to repay ~~at maturity $425~~short-term debt.

In April 2022, Ameren Missouri issued $525 million of 3.90% green first mortgage bonds due April 2052, with interest payable semiannually on April 1 and October 1 of each year, beginning October 1, 2022. Ameren ~~Missouri’s 6.40% senior secured notes in June 2017.~~Missouri received net proceeds of $519 million, which were used for capital expenditures and to repay short-term debt. Ameren Missouri intends to allocate an amount equal to the net proceeds to sustainability projects meeting certain eligibility criteria.

In ~~February 2016, $260~~November 2022, $47 million principal amount of Ameren Missouri’s ~~5.40% senior secured notes~~1.60% 1992 Series bonds matured and were repaid with ~~cash on hand and~~ commercial paper borrowings.

In December 2022, Ameren Missouri repaid $8 million of the remaining principal amount of the financing obligation related to the Peno Creek CT Energy Center to a trustee, which is authorized to utilize the cash only to pay equal amounts due to Ameren Missouri under related bonds issued by the city of Bowling Green and held by Ameren Missouri. The timing and amounts of payments due from Ameren Missouri under the agreement were equal to the timing and amount of bond service payments due to Ameren Missouri, resulting in no net cash flow. Under the terms of this agreement, Ameren Missouri was responsible for all operation and maintenance for the energy center. Ownership of

In January 2023, Ameren Missouri and Audrain County mutually agreed to terminate a financing obligation agreement related to the CT energy center in Audrain County, which was scheduled to expire in December 2023. No cash was exchanged associated with the termination of the agreement as the $240 million principal amount of the financing obligation due from Ameren Missouri was equal to the amount of bond service payments due to Ameren Missouri. Ownership of the energy center was transferred to Ameren Missouri in January 2023, at which time the property, plant, and equipment became subject to the lien of the Ameren Missouri mortgage bond indenture.

In June ~~2016,~~2021, Ameren Missouri issued ~~$150~~$525 million of ~~3.65% senior secured notes~~2.15% first mortgage bonds due ~~in April 2045,~~March 2032, with interest payable semiannually ~~in April~~on March 15 and ~~October~~September 15 of each year, beginning ~~in October 2016.~~March 15, 2022. Ameren Missouri received net proceeds of ~~$148~~$521 million, ~~from the June 2016 issuance,~~ which ~~was~~were used to repay ~~outstanding~~ short-term debt ~~including short-term debt that~~and for near-term capital expenditures. Ameren Missouri ~~incurred in connection with~~intends to allocate an amount equal to the ~~repayment of $114 million of its 4.75% senior secured notes that matured in April 2015.~~net proceeds to sustainability projects meeting certain eligibility criteria.

For information on Ameren Missouri’s capital contributions, refer to Capital Contributions in Note 13 – Related-party Transactions.

In ~~November 2017,~~March 2021, Ameren Illinois redeemed its 6.625% and 7.75% series preferred stock at par for $12 million and $1 million, respectively. The preferred stock of Ameren Illinois is reflected in “Noncontrolling Interests” on Ameren’s consolidated balance sheet.

In August 2022, Ameren Illinois issued $500 million of ~~3.70%~~3.85% first mortgage bonds due September 2032, with interest payable semiannually on March 1 and September 1 of each year, beginning March 1, 2023. Ameren Illinois received net proceeds of $496 million, which were used to repay $400 million principal amount of its 2.70% senior secured notes that matured in September 2022 and short-term debt.

In November 2022, Ameren Illinois issued $350 million of 5.90% first mortgage bonds due December ~~2047,~~2052, with interest payable semiannually on June 1 and December 1 of each year, beginning June 1, ~~2018.~~2023. Ameren Illinois received net proceeds of ~~$492~~$346 million, which were used to repay ~~outstanding~~ short-term ~~debt, including short-term debt that~~debt. Ameren Illinois ~~incurred in connection with~~intends to allocate an amount equal to the ~~repayment of $250 million of its 6.125% senior secured notes that matured in November 2017.~~net proceeds to sustainability projects meeting certain eligibility criteria.

In June 2016, Ameren Illinois’ $54 million principal amount of 6.20% senior secured notes and $75 million principal amount of 6.25% senior secured notes matured and were repaid with commercial paper borrowings.

In June 2021, Ameren Illinois issued $100 million of ~~its~~0.375% first mortgage bonds due June 2023, with interest payable semiannually on June 15 and December 15 of each year, beginning December 15, 2021. Ameren Illinois received net proceeds of $100 million, which were used to repay short-term debt.

For information on Ameren Illinois’ capital contributions, refer to Capital Contributions in Note 13 – Related-party Transactions.

In ~~June 2017,~~November 2021, pursuant to a note purchase agreement, ATXI agreed to issue ~~$450~~$95 million ~~principal amount~~ of ~~3.43%~~its 2.96% senior unsecured notes due ~~2050,~~2052, with interest payable semiannually on ~~the last day of~~ February 25 and August 25 of each year, beginning February ~~28, 2018,~~25, 2023, through a private placement offering exempt from registration under the Securities Act of 1933, as amended. In August 2022, ATXI issued the notes and received net proceeds of $95 million, which were used to refinance the remaining portion of an intercompany long-term note with Ameren (parent), repay a $50 million principal payment of its 3.43% senior unsecured notes in August 2022, and to repay short-term debt.

In November 2021, pursuant to a note purchase agreement, ATXI issued $75 million of its 2.45% senior unsecured notes due 2036, with interest payable semiannually on May 16 and November 16 of each year, beginning May 16, 2022, through a private placement offering exempt from registration under the Securities Act of 1933, as amended. ATXI ~~issued $150 million principal amount of the notes in June 2017 and the remaining $300 million principal amount of the notes in August 2017. ATXI~~ received net proceeds of ~~$449~~$75 million, ~~from the notes,~~ which were used ~~by ATXI~~to refinance a portion of an intercompany long-term note with Ameren (parent) and to repay ~~existing~~ short-term ~~and long-term affiliate~~ debt.

Ameren Missouri’s and Ameren Illinois’ indentures and articles of incorporation include covenants and provisions related to issuances of first mortgage bonds and preferred stock. Ameren Missouri and Ameren Illinois are required to meet certain ratios to issue additional first mortgage bonds and preferred stock. A failure to achieve these ratios would not result in a default under these covenants and provisions but would restrict the companies’ ability to issue bonds or preferred stock. The following table summarizes the required and actual interest coverage ratios for interest charges, dividend coverage ratios, and bonds and preferred stock issuable as of December 31, ~~2017~~,2022, at an assumed interest rate of 5%6% and dividend rate of 6%7%.

Ameren’s indenture does not require Ameren to comply with any quantitative financial covenants. The indenture does, however, include certain cross-default provisions. Specifically, either (1) the failure by Ameren to pay when due and upon expiration of any applicable grace period any portion of any Ameren indebtedness in excess of $25 million, or (2) the acceleration upon default of the maturity of any Ameren indebtedness in excess of $25 million under any indebtedness agreement, including borrowings under the Credit Agreements or the Ameren commercial paper program, constitutes a default under the indenture, unless such past due or accelerated debt is discharged or the acceleration is rescinded or annulled within a specified period.

Ameren Missouri and Ameren Illinois and certain other nonregistrant Ameren subsidiaries are subject to Section 305(a) of the Federal Power Act, which makes it unlawful for any officer or director of a public utility, as defined in the Federal Power Act, to participate in the making or paying of any dividend from any funds “properly included in capital account.” The FERC has consistently interpreted the provision to allow dividends to be paid as long as (1) the source of the dividends is clearly disclosed, (2) the dividends are not excessive, and (3) there is no self-dealing on the part of corporate officials. At a minimum, Ameren believes that dividends can be paid by its subsidiaries that are public utilities from net income and retained earnings. In addition, under Illinois law, Ameren Illinois and ATXI may not pay any dividend on ~~its~~their respective stock unless, among other things, ~~its~~their respective earnings and earned surplus are sufficient to declare and pay a dividend after ~~provision is~~provisions are made for reasonable and proper reserves, or unless Ameren Illinois or ATXI has specific authorization from the ICC.

Ameren Illinois’ articles of incorporation require dividend payments on its common stock to be based on ratios of common stock to total capitalization and other provisions related to certain operating expenses and accumulations of earned surplus. Ameren Illinois has made a commitment to the FERC to maintain a minimum 30% ratio of common stock equity to total capitalization. As of December 31, ~~2017~~,2022, using the FERC-agreed upon calculation method, Ameren Illinois’ ratio of common stock equity to total capitalization was ~~51%~~54%.

ATXI’s note purchase ~~agreement~~agreements includes financial covenants that require ATXI not to permit at any time (1) debt to exceed 70% of total capitalization or (2) secured debt to exceed 10% of total assets. The note purchase agreement also contains restrictive covenants that, among other things, restrict the ability of ATXI to (1) enter into certain transactions with affiliates; (2) consolidate, merge, transfer or lease all or substantially all of its assets; and (3) create liens.

At December 31, ~~2017,~~2022, the Ameren Companies were in compliance with the provisions and covenants contained in their indentures and articles of incorporation, as applicable, and ATXI was in compliance with the provisions and covenants contained in its note purchase ~~agreement.~~agreements. In order for the Ameren Companies to issue securities in the future, they will have to comply with all applicable requirements in effect at the time of any such issuances.

At December 31, ~~2017~~,2022, none of the Ameren Companies had any ~~significant~~material off-balance-sheet financing arrangements, other than ~~operating leases entered into~~their investments in variable interest entities and the ~~ordinary course~~multiple forward sale agreements under the ATM program relating to common stock. See Note 1 – Summary of ~~business, letters~~Significant Accounting Policies for further detail concerning variable interest entities.

The following table presents the components of “Other Income, ~~and Expenses”~~Net” in the Ameren Companies’ statements of income for the years ended December 31, ~~2017~~, ~~2016~~,2022, 2021, and ~~2015~~:2020:

We use derivatives to manage the risk of changes in market prices for natural gas, power, and uranium, as well as the risk of changes in rail transportation surcharges through fuel oil hedges. Such price fluctuations may cause the following:

The derivatives that we use to hedge these risks are governed by our risk management policies for forward contracts, futures, options, and swaps. Our net positions are continually assessed within our structured hedging programs to determine whether new or offsetting transactions are required. The goal of the hedging program is generally to mitigate financial risks while ensuring that sufficient volumes are available to meet our requirements. Contracts we enter into as part of our risk management program may be settled financially, settled by physical delivery, or net settled with the counterparty.

If we determine that a contract meets the definition of a derivative and is not eligible for the NPNS exception, we review the contract to determine whether the resulting gains or losses qualify for regulatory deferral. Derivative contracts that qualify for regulatory deferral are recorded at fair value, with changes in fair value recorded as regulatory assets or liabilities in the period in which the change occurs. We believe derivative losses and gains deferred as regulatory assets and liabilities are probable of recovery, or refund, through future rates charged to customers. Regulatory assets and liabilities are amortized to operating income as related losses and gains are reflected in rates charged to customers. Therefore, gains and losses on these derivatives have no effect on operating income. As of December 31, ~~2017~~2022 and ~~2016,~~2021, all contracts that met the definition of a derivative and were not eligible for the NPNS exception received regulatory deferral. Cash flows for all derivative financial instruments are classified in cash flows from operating activities.

The following table presents open gross commodity contract volumes by commodity type for derivative assets and liabilities as of December 31, 2022 and 2021. As of December 31, 2022, these contracts extended through October 2024, March 2029, May 2032, and March 2024 for fuel oils, natural gas, power, and uranium, respectively.

The following table presents the carrying value and balance sheet location of all derivative commodity contracts, none of which were designated as hedging instruments, as of December 31, ~~2017~~2022 and ~~2016~~:2021:

We believe that entering into master netting arrangements or similar agreements mitigates the level of financial loss that could result from default by allowing net settlement of derivative assets and liabilities. These master netting arrangements allow the counterparties to net settle sale and purchase transactions. Further, collateral requirements are calculated at the master netting arrangement or similar agreement level by counterparty.

The ~~Ameren Companies elect to present~~following table provides the ~~fair value~~recognized gross derivative balances and the net amounts of ~~derivative assets and derivative liabilities~~those derivatives subject to an enforceable master netting arrangement or similar agreement as of December 31, 2022 and 2021:

In determining our concentrations of credit risk related to derivative instruments, we review our individual counterparties and categorize each counterparty into groupings according to the primary business in which each engages. We calculate maximum exposures based on the gross fair value of financial instruments, including NPNS and other accrual contracts. These exposures are calculated on a gross basis, which include affiliate exposure not eliminated at the consolidated Ameren level. As of December 31, ~~2017,~~2022, if counterparty groups were to fail completely to perform on contracts, ~~the~~ Ameren, ~~Companies’~~Ameren Missouri, and Ameren Illinois’ maximum exposure ~~would have been immaterial with~~related to derivative assets, predominantly from financial institutions, was $74 million, $36 million, and $38 million, respectively. The potential loss on counterparty exposures may be reduced or ~~without~~eliminated by the application of master netting arrangements or similar agreements and collateral held. As of December 31, 2022, the potential loss after consideration of the application of master netting arrangements or similar agreements and collateral ~~held.~~held was immaterial for Ameren, Ameren Missouri, and Ameren Illinois.

Fair value is defined as the price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. We use various methods to determine fair value, including market, income, and cost approaches. With these approaches, we adopt certain assumptions that market participants would use in pricing the asset or liability, including assumptions about market risk or the risks inherent in the inputs to the valuation. Inputs to valuation can be readily observable, market-corroborated, or unobservable. We use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. Authoritative accounting guidance established a fair value hierarchy that prioritizes the inputs used to measure fair value. All financial assets and liabilities carried at fair value are classified and disclosed in one of the following three hierarchy levels:

The market approach is used to measure the fair value of equity securities held in Ameren Missouri’s nuclear decommissioning trust fund. Equity securities in this fund are representative of the S&P 500 index, excluding securities of Ameren Corporation, owners and/or operators of nuclear power plants, and the trustee and investment managers. The S&P 500 index comprises stocks of large-capitalization companies.

Fixed income securities are valued by using prices from independent industry-recognized data vendors who provide values that are either exchange-based or matrix-based. The fair value measurements of fixed-income securities classified as Level 2 are based on inputs other than quoted prices that are observable for the asset or liability. Examples are matrix pricing, market corroborated pricing, and inputs such as yield curves and indices. ~~Level 2 fixed income securities in the nuclear decommissioning trust fund are primarily corporate bonds, asset-backed securities, and United States agency bonds.~~

Derivative instruments classified as Level 2 are valued by corroborated observable inputs, such as pricing services or prices from similar instruments that trade in liquid markets. Our development and corroboration process entails obtaining multiple quotes or prices from outside sources. To derive our forward view to price our derivative instruments at fair value, we average the bid/ask spreads to the midpoints. ~~To validate forward prices obtained from outside parties, we compare the pricing to recently settled market transactions.~~ Additionally, a review of all sources is performed to identify any anomalies or potential errors. Further, we consider the volume of transactions on certain trading platforms in our reasonableness assessment of the averaged midpoints. The value of natural gas derivative contracts is based upon exchange closing prices without significant unobservable adjustments. The value of power ~~derivatives~~derivative contracts is based upon exchange closing prices or the use of multiple forward prices provided by third parties. ~~The prices are averaged and shaped to a monthly profile when needed without significant~~

We perform an analysis each quarter to determine the appropriate hierarchy level of the assets and liabilities subject to fair value measurements. Financial assets and liabilities are classified in their entirety according to the lowest level of input that is significant to the fair value measurement. All assets and liabilities whose fair value measurement is based on significant unobservable inputs are classified as Level 3.

The following table describes the valuation techniques and unobservable inputs utilized by the Ameren Companies for the fair value of financial assets and liabilities classified as Level 3 in the fair value hierarchy for the periods ended December 31, 2017 and 2016:

The following table sets forth, by level within the fair value hierarchy, our assets and liabilities measured at fair value on a recurring basis as of December 31, ~~2017~~:2022 and 2021:

See Note 10 – Retirement Benefits for tables that set forth, by level within the fair value hierarchy, Ameren’s pension and postretirement plan assets as of December 31, 2022 and 2021.

Quoted Prices in
Active Markets for
Identical Assets
or Liabilities
(Level 1)

Significant Other
Observable
Inputs
(Level 2)

Significant Other
Unobservable
Inputs
(Level 3)
Total
Assets:
Ameren
Derivative assets – commodity contracts^(a):

Fuel oils $ 4
$ —
$ 3
$ 7

Natural gas —
—
1
1

Power —
1
8
9

Total derivative assets – commodity contracts $ 4
$ 1
$ 12
$ 17

Nuclear decommissioning trust fund:
Cash and cash equivalents $ 2
$ —
$ —
$ 2

Equity securities:
U.S. large capitalization 468
—
—
468

Debt securities:
U.S. Treasury and agency securities —
125
—
125

Corporate bonds —
82
—
82

Other —
25
—
25

Total nuclear decommissioning trust fund $ 470
$ 232
$ —
$ 702
^(b)
Total Ameren $ 474
$ 233
$ 12
$ 719

Ameren Missouri
Derivative assets – commodity contracts^(a):

Fuel oils $ 4
$ —
$ 3
$ 7

Natural gas —
—
1
1

Power —
1
8
9

Total derivative assets – commodity contracts $ 4
$ 1
$ 12
$ 17

Level 3 fuel oils, natural gas and uranium derivative contract assets and liabilities measured at fair value on a recurring basis were immaterial for all periods presented. The following table presents the fair value reconciliation of Level 3 power derivative contract assets and liabilities measured at fair value on a recurring basis for the years ended December 31, 2022 and 2021:

All gains or losses related to our Level 3 derivative commodity contracts are expected to be recovered or returned through customer rates; therefore, there is no impact to either net income or other comprehensive income resulting from changes in the fair value of these instruments.

The following table describes the valuation techniques and significant unobservable inputs utilized for the fair value of our Level 3 power derivative contract assets and liabilities as of December 31, 2022 and 2021:

Quoted Prices in
Active Markets for
Identical Assets
or Liabilities
(Level 1)

Significant Other
Observable
Inputs
(Level 2)

Significant Other
Unobservable
Inputs
(Level 3)
Total
Nuclear decommissioning trust fund:
Cash and cash equivalents $ 2
$ —
$ —
$ 2

Equity securities:
U.S. large capitalization 468
—
—
468

Debt securities:
U.S. Treasury and agency securities —
125
—
125

Corporate bonds —
82
—
82

Other —
25
—
25

Total nuclear decommissioning trust fund $ 470
$ 232
$ —
$ 702
^(b)
Total Ameren Missouri $ 474
$ 233
$ 12
$ 719

Liabilities:
Ameren
Derivative liabilities – commodity contracts^(a):

Natural gas 1
25
4
30

Power —
—
196
196

Total Ameren $ 1
$ 25
$ 200
$ 226

Ameren Missouri
Derivative liabilities – commodity contracts^(a):

Natural gas —
7
1
8

Power —
—
1
1

Total Ameren Missouri $ —
$ 7
$ 2
$ 9

Ameren Illinois
Derivative liabilities – commodity contracts^(a):

Natural gas $ 1
$ 18
$ 3
$ 22

Power —
—
195
195

Total Ameren Illinois $ 1
$ 18
$ 198
$ 217

During its return to full power after the completion of a refueling and maintenance outage in late December 2020, the Callaway Energy Center experienced a non-nuclear operating issue related to its generator. After replacement of certain key components of the generator, the energy center returned to service in early August 2021. The cost of generator repairs was approximately $60 million, which was largely capital expenditures. In April 2021, Ameren Missouri’s insurance claims were accepted by NEIL, which covered a significant portion of the capital expenditures and covered lost sales of up to $4.5 million weekly after March 17, 2021. Insurance recoveries related to lost sales were reflected in electric operating revenues and included in net energy costs under the FAC. Insurance recoveries related to the capital expenditures were reflected as a reduction to property, plant, and equipment. Ameren Missouri has received all insurance recoveries related to lost sales and the capital expenditures insurance claims.

Under the ~~NWPA,~~Nuclear Waste Policy Act of 1982, as amended, the DOE is responsible for disposing of spent nuclear fuel from the Callaway ~~energy center~~

Electric rates charged to customers provide for the recovery of the Callaway ~~energy center’s~~Energy Center’s decommissioning costs, which include decontamination, dismantling, and site restoration costs, over the expected life of the nuclear energy center. Amounts collected from customers are deposited into the external nuclear decommissioning trust fund to provide for the Callaway ~~energy center’s~~Energy Center’s decommissioning. It is assumed that the Callaway ~~energy center~~Energy Center site will be ~~eventually~~ decommissioned after its retirement through the immediate dismantlement method and removed from service. The Callaway Energy Center’s operating license expires in 2044. Ameren and Ameren Missouri have recorded an ARO for the Callaway ~~energy center~~Energy Center decommissioning costs at fair ~~value, which represents the present value of estimated future cash outflows.~~value. Annual decommissioning costs of $7 million are included in the costs used to establish electric rates for Ameren Missouri’s customers. Every three years, the MoPSC requires Ameren Missouri to file an updated cost study and funding analysis for decommissioning its Callaway ~~energy center.~~Energy Center. An updated cost study and funding analysis was filed with the MoPSC in ~~September 2017~~November 2020 and reflected within the ARO. In ~~January 2018,~~February 2021, the MoPSC approved no change in electric rates for decommissioning costs ~~based on~~consistent with Ameren Missouri’s updated cost study and funding analysis.

Ameren and Ameren Missouri have classified the investments in debt and equity securities that are held in the nuclear decommissioning trust fund as available for sale, and have recorded all such investments at their fair market value at December 31, 2022 and 2021. Investments in the nuclear decommissioning trust fund have a target allocation of 60% to 70% in equity securities, with the balance invested in debt securities.

The fair value of the trust fund for Ameren Missouri’s Callaway ~~energy center~~Energy Center is reported as “Nuclear decommissioning trust fund” in Ameren’s and Ameren Missouri’s balance sheets. This amount is legally restricted and may be used only to fund the costs of nuclear decommissioning. Changes in the fair value of the trust fund are recorded as an increase or decrease to the nuclear decommissioning trust fund, with an offsetting adjustment to the regulatory liability related to AROs. This reporting is consistent with the method used to account for the decommissioning costs recovered in rates. See Note 2 – Rate and Regulatory Matters for the regulatory ~~liability.~~liability recorded at December 31, 2022. If the assumed return on trust assets is not earned, Ameren Missouri believes that it is probable that any additional funding requirements resulting from such earnings deficiency will be recovered in customer rates.

The following table presents proceeds from the ~~sale~~sales and maturities of investments in Ameren Missouri’s nuclear decommissioning trust fund and the gross realized gains and losses resulting from those sales for the years ended December 31, ~~2017, 2016,~~2022, 2021, and ~~2015:~~2020:

2017 2016 2015
Proceeds from sales and maturities $ 396
$ 377
$ 349
Gross realized gains 13
7
8
Gross realized losses 5
4
2

The following table presents the costs and fair values of investments in debt securities in Ameren’s and Ameren Missouri’s nuclear decommissioning trust fund according to their contractual maturities at December 31, ~~2017~~:2022:

The following table presents insurance coverage at Ameren Missouri’s Callaway ~~energy center~~Energy Center at ~~December 31, 2017. The property coverage and the nuclear liability coverage renewal dates are April 1 and~~ January 1, ~~respectively,~~2023:

The Price-Anderson Act is a federal law that limits the liability for claims from an incident involving any licensed United States commercial nuclear energy center. The limit is based on the number of licensed reactors. The limit of liability and the maximum potential annual payments are adjusted at least every five years for inflation to reflect changes in the Consumer Price Index. The most recent five-year inflationary adjustment became effective in ~~September 2013.~~November 2018. Owners of a nuclear reactor cover this exposure through a combination of private insurance and mandatory participation in a financial protection pool, as established by the Price-Anderson Act.

Losses resulting from terrorist attacks on nuclear facilities insured by NEIL are subject to industrywide ~~aggregates. Terrorist~~aggregates, such that terrorist acts against one or more commercial nuclear power plants ~~insured by NEIL or EMANI~~ within a stated time period would be treated as a single event, and the owners of the nuclear power plants would share ~~one full~~the limit of liability. NEIL policies have an aggregate limit of $3.2 billion within a 12-month period for radiation events, or $1.8 billion for events not involving radiation ~~contamination.~~contamination, resulting from terrorist attacks. The EMANI policies ~~have an aggregate limit~~are not subject to industrywide aggregates in the event of ~~€600 million for radiation and nonradiation events within a period of 72 hours.~~terrorist attacks on nuclear facilities.

If losses from a nuclear incident at the Callaway ~~energy center~~Energy Center exceed the ~~insurance~~ limits of, or are not covered by insurance, or if coverage is unavailable, Ameren Missouri is at risk for any uninsured losses. If a serious nuclear incident were to occur, it could have a material adverse effect on Ameren’s and Ameren Missouri’s results of operations, financial position, or liquidity.

The primary objective of the Ameren pension and postretirement benefit plans is to provide eligible employees with pension and postretirement health care and life insurance benefits. Ameren has defined benefit pension ~~and postretirement benefit~~ plans covering substantially all of its ~~union employees. Ameren has defined benefit pension plans covering substantially all of its non-union~~ employees and has a postretirement benefit ~~plans~~plan covering non-union employees hired before October ~~2015. Ameren uses a measurement date of December 31~~

Ameren’s ~~unfunded obligation under its~~ pension and other postretirement benefit plans ~~was $551~~were overfunded by $377 million and ~~$774~~$717 million in the aggregate as of December 31, ~~2017~~2022 and ~~2016,~~2021, respectively. These net ~~liabilities~~assets are recorded in ~~“Other current liabilities” and~~ “Pension and other postretirement ~~benefits”~~benefits,” “Other current liabilities,” and “Other deferred credits and liabilities” on Ameren’s consolidated balance sheet. The decrease in the ~~unfunded obligation~~overfunded pension and postretirement benefit plans during ~~2017~~2022 was primarily the result of ~~a larger-than-expected increase in the return~~losses on plan assets of the pension and postretirement trusts during 2022 offset by a 50255 basis point ~~decrease~~increase in the pension and other postretirement benefit plan discount rates used to determine the present value of the obligation. The ~~decrease in the unfunded obligation~~overfunded pension and other postretirement benefit plans also resulted in ~~a decrease to “Regulatory assets”~~regulatory liabilities on Ameren’s, Ameren Missouri’s, and Ameren Illinois’ balance sheets.

The following table presents the net benefit ~~liability~~liability/(asset) recorded on the balance sheets ~~of each of the Ameren Companies~~ as of December 31, ~~2017~~2022 and ~~2016~~:2021:

2017
2016
Ameren^(a)
$ 551
$ 774
Ameren Missouri 215
293
Ameren Illinois^(b)
213
315

2017 2016

Pension Benefits^(a)

Postretirement
Benefits^(a)

Pension Benefits^(a)

Postretirement
Benefits^(a)
Accumulated benefit obligation at end of year $ 4,577
$ (b)
$ 4,288
$ (b)
Change in benefit obligation:
Net benefit obligation at beginning of year $ 4,518
$ 1,170
$ 4,197
$ 1,094
Service cost 93
21
81
19
Interest cost 179
47
185
50
Participant contributions —
8
—
8
Actuarial loss 255
53
265
52
Benefits paid (218 ) (59 ) (210 ) (54 )
Federal subsidy on benefits paid (b)
—
(b)
1
Net benefit obligation at end of year 4,827
1,240
4,518
1,170
Change in plan assets:
Fair value of plan assets at beginning of year 3,813
1,101
3,653
1,071
Actual return on plan assets 634
171
313
73
Employer contributions 64
2
57
2
Federal subsidy on benefits paid (b)
—
(b)
1
Participant contributions —
8
—
8
Benefits paid (218 ) (59 ) (210 ) (54 )
Fair value of plan assets at end of year 4,293
1,223
3,813
1,101
Funded status – deficiency 534
17
705
69
Accrued benefit cost at December 31 $ 534
$ 17
$ 705
$ 69
Amounts recognized in the balance sheet consist of:
Current liability^(c)
3
3
3
2
Noncurrent liability 531
14
702
67
Net liability recognized $ 534
$ 17
$ 705
$ 69
Amounts recognized in regulatory assets consist of:
Net actuarial (gain) loss $ 374
$ (69 ) $ 535
$ (29 )
Prior service credit (3 ) (3 ) (4 ) (8 )
Amounts (pretax) recognized in accumulated OCI consist of:
Net actuarial loss 30
2
43
—
Prior service credit —
—
—
(1 )
Total $ 401
$ (70 ) $ 574
$ (38 )

Ameren determines discount rate assumptions by identifying a theoretical settlement portfolio of high-quality corporate bonds sufficient to provide for a plan’s projected benefit payments. The settlement portfolio of bonds is selected from a pool of ~~more than~~ ~~600~~approximately 850 high-quality corporate bonds. A single discount rate is then determined; that rate results in a discounted value of the plan’s benefit payments that equates to the market value of the selected bonds. In ~~addition, during 2017,~~2022, Ameren ~~adopted~~elected to continue to use the Society of Actuaries ~~2017~~mortality table and the Society of Actuaries 2020 Mortality Improvement Scale. ~~The updated scale assumes a lower rate of mortality improvement as compared to the 2016 Mortality Improvement Scale that Ameren~~

Pension benefits are based on the employees’ years of service, age, and compensation. Ameren’s pension plans are funded in compliance with income tax regulations, federal funding requirements, and other regulatory requirements. As a result, Ameren expects to fund its pension ~~plan~~plans at a level equal to the greater of the pension cost or the legally required minimum contribution. ~~Considering~~Based on its assumptions at December 31, ~~2017~~,2022, its investment performance in ~~2017,~~2022, and its pension funding policy, Ameren does not expect to make material contributions in 2023 through 2025, and expects to make ~~annual~~aggregate contributions of ~~less than~~ $1$170 million to ~~$60 million~~ in ~~each of the next five years, with aggregate estimated contributions of~~ ~~$120 million~~.2026 and 2027. Ameren Missouri and Ameren Illinois ~~expect~~estimate that their portion of the future funding requirements towill be ~~35%~~40% and ~~55%~~50%, respectively. These ~~amounts are estimates. They~~estimated contributions may change based on actual investment performance, changes in interest rates, changes in our assumptions, changes in government regulations, and any voluntary contributions. Our funding policy for postretirement benefits is primarily to fund the Voluntary Employee Beneficiary Association (VEBA) trusts to match the annual postretirement expense.

The following table presents the cash contributions made to our defined benefit retirement ~~plan~~plans and to our postretirement ~~plans~~plan during ~~2017~~, ~~2016~~,2022, 2021, and ~~2015~~:2020:

Ameren manages plan assets in accordance with the “prudent investor” guidelines contained in ERISA. The investment committee, which includes members of senior management, approves and implements investment strategy and asset allocation guidelines for the plan assets. The investment committee’s goals are twofold: first, to ensure that sufficient funds are available to provide the benefits at the time they are payable; and second, to maximize total return on plan assets and to minimize expense volatility consistent with its tolerance for risk. Ameren delegates the task of investment management to specialists in each asset class. As appropriate, Ameren provides each investment manager with guidelines that specify allowable and prohibited investment types. The investment committee regularly monitors manager performance and compliance with investment guidelines.

The expected return on plan assets assumption is based on historical and projected rates of return for current and planned asset classes in the investment portfolio. Projected rates of return for each asset class were estimated after an analysis of historical experience, future expectations, and the volatility of the various asset classes. After considering the target asset allocation for each asset class, we ~~adjusted~~reviewed the overall expected rate of return for the portfolio for historical and expected experience of active portfolio management results compared with benchmark returns and for the effect of expenses paid from plan assets. Ameren will use an expected return on plan assets for its pension and postretirement plan assets of ~~7.00%~~6.75% in ~~2018. No plan assets are expected to be returned to Ameren during 2018.~~2023.

Ameren’s investment committee strives to assemble a portfolio of diversified assets that does not create a significant concentration of risks. The investment committee develops asset allocation guidelines between asset classes, and it creates diversification through investments in assets that differ by type (equity, debt, real ~~estate, private equity)~~estate), duration, market capitalization, country, style (growth or value), and industry, among other factors. The diversification of assets is displayed in the target allocation table below. The investment committee also routinely rebalances the plan assets to adhere to the diversification goals. The investment committee’s strategy reduces the concentration of investment risk; however, Ameren is still subject to overall market risk.

Effective January 2020, Ameren’s investment committee developed and implemented a liability hedging investment strategy for its qualified pension plans designed to reduce interest rate risk as part of an objective for its long-term investment strategy. The plan invests in derivative instruments mainly consisting of interest rate futures intended to extend the duration of the pension plan assets so that the assets are more closely aligned with the duration of the liabilities. In addition, part of Ameren’s investment strategy includes participation in a securities lending program, which allows it to lend eligible securities to third party borrowers. All loans are collateralized by at least 103% of the loaned asset’s market value and the collateral is invested in the form of cash, government obligations, and U.S. agency obligations. Ameren’s fair value of securities loaned was $239 million and $374 million as of December 31, 2022 and 2021, respectively. Cash and securities obtained as collateral exceeded the fair value of the securities loaned as of December 31, 2022 and 2021.

The following table presents our target allocations ~~for 2018~~ and our pension and postretirement plans’ asset categories as of December 31, ~~2017~~2022 and ~~2016~~:2021:

Investments in the pension and postretirement benefit plans were stated at fair value as of December 31, ~~2017. The fair~~2022. Fair value ~~of an asset~~ is defined as the ~~amount~~price that would be received ~~upon its sale~~for an asset in the principal or most advantageous market for the asset in an orderly transaction between market participants aton the measurement date. Cash and cash equivalents have initial maturities of three months or less and are recorded at cost plus accrued interest. ~~The carrying amounts of cash and cash equivalents approximate fair value because of the short-term nature of these instruments.~~ Investments traded in active markets on national or international securities exchanges are valued at closing prices on the measurement date or, if that is not a business day, on the last business day before that date. Securities traded in over-the-counter markets are valued by quoted market prices, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency. Investments measured under NAV as a practical expedient are based on the fair values of the underlying assets provided by the funds and their administrators. The fair value of real estate investments is based on NAV; it is determined by annual appraisal reports prepared by an independent real estate appraiser. Investments measured at NAV often provide for daily, monthly, or quarterly redemptions with 60 or less days of notice depending on the fund. For some funds, redemption may also require approval from the fund’s board of directors. Derivative contracts are valued at fair value, as determined by the investment managers (or independent third parties on behalf of the investment managers), who use proprietary models and take into consideration exchange quotations on underlying instruments, dealer quotations, and other market information.

Quoted Prices in
Active Markets for
Identified Assets
(Level 1)

Significant Other
Observable
Inputs
(Level 2)

Significant Other
Unobservable
Inputs
(Level 3)
Measured at NAV Total
Cash and cash equivalents $ —
$ —
$ —
$ 25
$ 25
Equity securities:
U.S. large-capitalization —
—
—
1,523
1,523
U.S. small- and mid-capitalization 379
—
—
—
379
International and emerging markets 179
—
—
450
629
Debt securities:
Corporate bonds —
726
—
15
741
Municipal bonds —
91
—
—
91
U.S. Treasury and agency securities 8
816
—
—
824
Other —
7
—
—
7
Real estate —
—
—
196
196
Private equity —
—
—
4
4
Total $ 566
$ 1,640
$ —
$ 2,213
$ 4,419
Less: Medical benefit assets at December 31^(a)
(153 )
Plus: Net receivables at December 31^(b)
27
Fair value of pension plans’ assets at December 31 $ 4,293

The following table presents the components of the net periodic benefit cost (income) of Ameren’s pension and postretirement benefit plans during ~~2017~~, ~~2016~~,2022, 2021, and ~~2015~~:2020:

The Ameren Companies are responsible for their share of the pension and postretirement benefit ~~costs.~~costs (income). The following table presents the pension ~~costs~~ and ~~the~~ postretirement benefit costs (income) incurred for the years ended December 31, ~~2017~~, ~~2016~~,2022, 2021, and ~~2015~~:2020:

Pension Costs Postretirement Costs
2017 2016 2015 2017 2016 2015
Ameren Missouri^(a)
$ 24
$ 26
$ 54
$ (4 ) $ (5 ) $ 8
Ameren Illinois 41
22
38
(14 ) (13 ) (3 )
Other (1 ) (4 ) —
—
(1 ) (1 )
Ameren 64
44
92
(18 ) (19 ) 4

Pension Benefits Postretirement Benefits

Paid from
Qualified
Trust Funds

Paid from
Company
Funds

Paid from
Qualified
Trust Funds

Paid from
Company
Funds
2018 $ 255
$ 3
$ 57
$ 2
2019 261
3
59
2
2020 266
3
62
2
2021 277
3
64
2
2022 280
3
65
2
2023 – 2027
1,421
13
331
12

Ameren sponsors a 401(k) plan for eligible employees. The Ameren 401(k) plan covered all eligible Ameren employees at December 31, ~~2017~~.2022. The plan allows employees to contribute a portion of their compensation in accordance with specific guidelines. Ameren matches a percentage of the employee contributions up to certain limits. The following table presents the portion of the matching contribution to the Ameren 401(k) plan attributable to ~~the continuing operations for~~ each of the Ameren Companies for the years ended December 31, ~~2017~~, ~~2016~~,2022, 2021, and ~~2015~~:2020:

~~The 2014 Incentive Plan is~~ Ameren’s long-term ~~stock compensation~~incentive plan available for eligible employees and ~~directors.~~directors, the 2014 Omnibus Incentive Compensation Plan (2014 Plan), was replaced prospectively by the 2022 Omnibus Incentive Compensation Plan (2022 Plan) effective May 12, 2022. The ~~2014 Incentive~~2022 Plan provides for a maximum of 88.8 million common shares to be available for grant to eligible employees and ~~directors.~~directors, and retains many of the features of the 2014 Plan. At December 31, ~~2017,~~2022, there were ~~4.9~~8.6 million common shares remaining for grant. The 2022 Plan permits the grant ~~under the 2014 Incentive Plan. The 2014 Incentive Plan awards may be stock options, stock appreciation rights,~~of restricted stock, restricted stock units, stock options (incentive stock options and nonqualified stock options), stock appreciation rights, performance ~~shares, performance share units,~~awards, cash-based awards and other stock-based awards. Ameren used newly issued shares to fulfill its stock-based compensation obligations for 2022, 2021, and 2020, and intends to use newly issued shares to fulfill its stock-based compensation obligations for 2023.

AThe following table summarizes Ameren’s outstanding performance share unit ~~vests~~ and ~~entitles an employee~~restricted stock unit activity for the year ended December 31, 2022:

A market condition performance share unit vests and entitles an employee to receive shares of Ameren common stock (plus accumulated dividends) if, at the end of the three-year performance period, certain specified market conditions have been met and if the individual remains employed by Ameren through the required vesting period. The vesting period for share units awarded extends beyond the three-year performance period to the payout date, which is approximately 37 to 38 months after the grant date.

The fair value of each share unit ~~awarded under the 2014 Incentive Plan~~ is based on Ameren’s closing common share price at December ~~31st~~31 of the year prior to the award year and ~~lattice simulations. Lattice simulations are~~a Monte Carlo simulation. The Monte Carlo simulation is used to estimate expected share payout based on Ameren’s ~~total shareholder return~~TSR for a ~~3-year~~three-year performance period relative to the designated peer group beginning January 1st of the award year. The ~~simulations~~simulation can produce a greater fair value for the share unit than the applicable closing common share price because ~~they include~~it includes the weighted payout scenarios in which an increase in the share price has ~~occurred.~~occurred and/or in which the payout is above 100% due to Ameren’s projected TSR performance. The significant assumptions used to calculate fair value also include a three-year risk-free rate, Ameren’s common stock volatility, and volatility for the peer ~~group, and Ameren’s attainment of a three-year average earnings per share threshold during the performance period.~~group. The following table presents the fair value of each share unit ~~awarded under the 2014 Incentive Plan~~ along with the significant assumptions used to calculate the fair value of each share unit for the years ended December 31, ~~2017, 2016,~~2022, 2021, and ~~2015:~~2020:

A performance condition share unit vests and entitles an employee to receive shares of Ameren common stock (plus accumulated dividends) if, at the end of the three-year performance period, Ameren has met the specified performance condition and if the individual remains employed by Ameren through the required vesting period. The vesting period for share units awarded extends beyond the three-year performance period to the payout date, which is approximately 37 to 38 months after the grant date. In the event of a participant’s death or retirement at age 55 or older with five years or more of service, awards vest on a pro-rata basis over the three-year performance period. The exact number of shares issued pursuant to a share unit varies from 0% to 200% of the target award, depending on actual performance conditions achieved. The specified performance condition in each award year is based on Ameren’s clean energy transition. The grant-date fair value for an individual outcome of a performance condition is determined by Ameren’s closing common share price on the grant date.

Restricted stock units vest and entitle an employee to receive shares of Ameren common stock (plus accumulated dividends) if the individual remains employed with Ameren through the payment date of the awards. Generally, in the event of a participant’s death or retirement at age 55 or older with five years or more of service, awards vest on a pro-rata basis. The payout date of the awards is approximately 37 to 38 months after the grant date. The fair value of each restricted stock unit is determined by Ameren’s closing common share price on the grant date.

The following table presents the stock-based compensation expense for the years ended December 31, 2022, 2021, and 2020:

Ameren settled performance share units and restricted stock units of $47 million, $50 million, and $58 million for the years ended December 31, 2022, 2021, and 2020. There were no significant stock-based compensation costs capitalized during the years ended December 31, 2022, 2021, and 2020. As of December 31, 2022, total compensation cost of $38 million related to outstanding awards not yet recognized is expected to be recognized over a weighted-average period of 21 months.

For the years ended December 31, 2022, 2021, and 2020, excess tax benefits associated with the settlement of stock-based compensation awards reduced income tax expense by $5 million, $5 million, and $8 million, respectively.

The ~~TCJA~~IRA was enacted in August 2022, and includes various income tax provisions, among other things. The law extends federal production and investment tax credits for projects beginning construction through 2024 and allows for a 10% adder to the production and investment tax credits for siting projects at existing energy communities as defined in the law, which includes sites previously used for coal-fired generation. The law also creates new federal production and investment tax credits for projects placed in service after 2024. The federal production and investment tax credits will apply to renewable energy production and investments, along with certain nuclear energy production, and will be phased out beginning in 2033, at the earliest. The phase-out is triggered when greenhouse gas emissions from the electric generation industry are reduced by at least 75% from the annual 2022 emission rate or at the beginning of 2033, whichever is later. The law allows for transferability to an unrelated party for cash of certain tax credits generated after 2022. In addition, the new law imposes a 15% minimum tax on ~~December 22, 2017. Substantially all of~~adjusted financial statement income, as defined in the ~~provisions of the TCJA affecting the Ameren Companies, other than certain transition depreciation rules, are~~law, assessed against corporations whose average annual adjusted financial statement income exceeds $1 billion for three consecutive preceding tax years, effective for ~~taxable~~tax years beginning after December 31, 2017. The TCJA includes significant changes to the Internal Revenue Code, including amendments that significantly change the taxation of business entities and specific provisions related to regulated public utilities. The most significant change that affects the Ameren Companies is the reduction in the federal

Ameren Missouri Ameren Illinois Ameren
2017
Federal statutory corporate income tax rate: 35 % 35 % 35 %
Increases (decreases) from:
Depreciation differences 1
(1 ) —
Amortization of deferred investment tax credit (1 ) —
(1 )
State tax 4
6
6
TCJA 6
(1 ) 14
Tax credits (1 ) —
—
Other permanent items —
(1 ) (2 )
Effective income tax rate 44 % 38 % 52 %
2016
Federal statutory corporate income tax rate: 35 % 35 % 35 %
Increases (decreases) from:
Depreciation differences 1
—
—
Amortization of deferred investment tax credit (1 ) —
—
State tax 3
5
4
Stock-based compensation^(a)
—
—
(2 )
Valuation allowance —
—
1
Other permanent items —
(2 ) (1 )
Effective income tax rate 38 % 38 % 37 %
2015
Federal statutory corporate income tax rate: 35 % 35 % 35 %
Increases (decreases) from:
Depreciation differences —
(2 ) (1 )
Amortization of deferred investment tax credit (1 ) —
(1 )
State tax 3
5
5
Other permanent items —
(1 ) —
Effective income tax rate 37 % 37 % 38 %

The following table presents the accumulated deferred income tax assets and liabilities recorded as a result of temporary differences and accumulated deferred investment tax credits at December 31, ~~2017~~2022 and ~~2016~~:2021:

Ameren Missouri Ameren Illinois Other Ameren
2017
Accumulated deferred income taxes, net liability (asset):
Plant related $ 2,064
$ 1,264
$ 146
$ 3,474
Regulatory assets and liabilities, net (317 ) (206 ) (24 ) (547 )
Deferred employee benefit costs (53 ) (17 ) (61 ) (131 )
Revenue requirement reconciliation adjustments —
20
—
20
Tax carryforwards (31 ) (43 ) (287 ) (361 )
Other (13 ) 3
61
51
Total net accumulated deferred income tax liabilities (assets) $ 1,650
$ 1,021
$ (165 ) $ 2,506
2016
Accumulated deferred income taxes, net liability (asset):
Plant related $ 3,103
$ 1,769
$ 147
$ 5,019
Regulatory assets and liabilities, net 75
(1 ) —
74
Deferred employee benefit costs (76 ) (38 ) (97 ) (211 )
Revenue requirement reconciliation adjustments —
34
—
34
Tax carryforwards (66 ) (138 ) (472 ) (676 )
Other (23 ) 5
42
24
Total net accumulated deferred income tax liabilities (assets) $ 3,013
$ 1,631
$ (380 ) $ 4,264

As of December 31, ~~2017~~2022 and ~~2016,~~2021, the Ameren Companies did not record any uncertain tax positions.

~~In 2015, final settlements for tax years 2012 and 2013 were reached with the IRS. The 2015 settlement~~Ameren is a part of the ~~2013~~IRS’s compliance assurance process program, which involves real-time review of compliance with federal income tax ~~year affected discontinued operations. See Note 1 – Summary of Significant Accounting Policies for additional information.~~

Ameren Missouri has an uncertain tax position tracker. Under Ameren Missouri’s regulatory framework, uncertain tax positions do not reduce Ameren Missouri’s electric rate base. When an uncertain income tax position liability is resolved, the MoPSC requires, through the uncertain tax position tracker, the creation of a regulatory asset or regulatory liability to reflect the time value, ~~using~~with a return at the ~~weighted-average cost of capital~~applicable WACC included in each of the electric rate orders in effect before the tax position was resolved, of the difference between the uncertain tax position liability that was excluded from rate base and the final tax liability. The resulting regulatory asset or liability will affect earnings in the year it is created. It will then ~~will~~ be amortized over three years, beginning on the effective date of new rates established in the next electric service regulatory rate review.

In the normal course of business, Ameren Missouri and Ameren Illinois ~~have engaged in, and may in the future~~ engage in affiliate transactions. These transactions primarily consist of natural gas and power purchases and sales, services received or rendered, and borrowings and lendings. Transactions between Ameren’s subsidiaries are reported as affiliate transactions on their individual financial statements, but those transactions are eliminated in consolidation for Ameren’s consolidated financial statements. Below are the material related-party agreements.

Ameren Illinois must acquire capacity and energy sufficient to meet its obligations to customers. Ameren Illinois uses periodic RFP processes, administered by the IPA and approved by the ICC, to contract capacity and energy on behalf of its customers. Ameren Missouri participates in the RFP process and has been a winning supplier for certain periods.

In a procurement ~~event~~events in ~~2012,~~2021, Ameren Missouri contracted to supply a portion of Ameren Illinois’ capacity requirements for $3$2 million ~~for the 12 months ended~~from June 2022 through May ~~31, 2015. In a procurement event in 2015, Ameren Missouri contracted to supply a portion of Ameren Illinois’ capacity requirements for $15 million for the 12 months ending May 31, 2017.~~2023.

Based on the outcome of IPA-administered procurement events, Ameren Missouri and Ameren Illinois have entered into energy product agreements by which Ameren Missouri agreed to sell, and Ameren Illinois agreed to purchase, a set amount of ~~megawatthours~~MWhs at a predetermined price over a specified period of time. The following table presents the ~~agreements the companies have entered into, as well as the~~ specified performance period, average price per MWh, and amount of ~~megawatthours~~MWhs included in ~~each agreement:~~the agreements:

Under the terms of the Illinois energy product agreements entered into through RFP processes administered by the IPA, suppliers must post collateral under certain market conditions to protect Ameren Illinois in the event of nonperformance. The collateral postings are unilateral, which means that only the suppliers can be required to post collateral. Therefore, Ameren Missouri, as a winning supplier in the RFP process, may be required to post collateral. As of December 31, ~~2017~~2022 and ~~2016,~~2021, there were no collateral postings required of Ameren Missouri related to the Illinois energy product agreements.

Ameren Missouri and Ameren Illinois are parties to an interconnection agreement ~~for~~that governs the ~~use~~connection of their respective transmission lines and other facilities used for the distribution of power. These agreements have no contractual expiration date, but may be terminated by either party with three years’ notice.

Ameren Missouri and ATXI are parties to an interconnection agreement that governs the connection of the High Prairie Renewable Energy Center to an ATXI transmission line that allows Ameren Missouri to distribute power generated from the High Prairie Renewable Energy Center.

Ameren Services provides support services to its affiliates. The costs of support services including wages, employee benefits, professional services, and other expenses, are based on, or are an allocation of, actual costs incurred. The support services agreement can be terminated at any time by the mutual agreement of Ameren Services and that affiliate or by either party with 60 days’ notice before the end of a calendar year.

In addition, Ameren Missouri and Ameren Illinois provide affiliates ~~primarily Ameren Services,~~ with access to their facilities for administrative ~~purposes.~~purposes and with use of other assets. The costs of the rent and facility services and other assets are based on, or are an allocation of, actual costs incurred.

~~Separately,~~ Ameren Missouri and Ameren Illinois also provide storm-related and miscellaneous support services to each other on an as-needed basis.

Ameren Missouri and Ameren Illinois had long-term receivables included in “Other assets” from Ameren Services of $41 million and $43 million, respectively, as of December 31, 2022, and $77 million and $80 million, respectively, as of December 31, 2021, related to Ameren Services’ allocated portion of Ameren’s pension and postretirement benefit plans.

Ameren Missouri and Ameren Illinois each receives transmission services from ATXI for ~~its~~their respective retail ~~load~~loads.

See Note 4 – Short-term Debt and Liquidity for a discussion of affiliate borrowing arrangements.

See Note 1 – Summary of Significant Accounting Policies for a discussion of the tax allocation agreement. AsThe following table presents the affiliate balances related to income taxes for Ameren Missouri and Ameren Illinois as of December 31, ~~2017~~2022 and ~~2016, Ameren Missouri had income taxes payable to Ameren (parent) of $11 million and $16 million, respectively, included~~2021:

The following table presents cash capital contributions received ~~related to the tax allocation agreement.~~

In 2015, Ameren Missouri received cash capital contributions of $224 million from Ameren (parent) as a result of the tax allocation agreement, which included the accrued capital contribution from 2014. Additionally, as of December 31, 2015, Ameren Missouri accrued a $38 million capital contribution related to the same agreement. In 2015, Ameren Illinois received cash capital contributions of $25 million from Ameren (parent).

We are involved in legal, tax, and regulatory proceedings before various courts, regulatory commissions, authorities, and governmental agencies with respect to matters that arise in the ordinary course of business, some of which involve substantial amounts of money. We believe that the final disposition of these proceedings, except as otherwise disclosed in ~~these~~the notes to our financial statements, will not have a material adverse effect on our results of operations, financial position, or liquidity.

See also Note 1 – Summary of Significant Accounting Policies, Note 2 – Rate and Regulatory Matters, Note 9 – Callaway Energy Center, ~~and~~ Note 13 – Related-party Transactions, and Note 15 – Supplemental Information in this report.

~~We lease various facilities, office equipment, plant equipment,~~Our electric generation, transmission, and ~~rail cars under capital and operating leases. The following table presents our lease obligations at~~ ~~December 31, 2017~~:

Additionally, Ameren Missouri’s ~~current plan~~wind generation facilities may be subject to operating restrictions to limit the impact on protected species. From April through October, in both 2021 and 2022, Ameren Missouri's High Prairie Renewable Energy Center curtailed nighttime operations to limit impacts on protected species. Ameren Missouri resumed nighttime operations in November 2022 as the critical biological season had ended. Seasonal nighttime curtailment will begin again by April 2023, but the extent and duration of the curtailment is unknown at this time as assessment of mitigation technologies is ongoing. In the 2022 electric service regulatory rate review, the MoPSC staff and the MoOPC have recommended reductions to the revenue requirement associated with the curtailment of the High Prairie Renewable Energy Center. See Note 2 – Rate and Regulatory Matters for ~~compliance with existing air emission regulations includes burning ultra-low-sulfur coal and installing new or optimizing existing pollution control equipment.~~ additional information.

Ameren and Ameren Missouri estimate that they will need to make capital expenditures of ~~$325~~$90 million to ~~$425~~$120 million from ~~2018~~2023 through ~~2022~~2027 in order to comply with existing environmental regulations. Additional environmental controls beyond ~~2022~~2027 could be required. This estimate of capital expenditures includes ~~expenditures~~ash pond closure and corrective action measures required by the CCR ~~regulations, by the Clean Water Act rule applicable~~Rule and potential modifications to cooling water intake structures at existing power plants ~~and by effluent limitation guidelines applicable to steam electric generating units,~~under Clean Water Act rules, all of which are discussed below. In addition to planned retirements of coal-fired energy centers as set forth in the 2022 Change to the 2020 IRP filed with the MoPSC in June 2022 and as noted in the NSR and Clean Air Act litigation and Illinois emissions standards discussed below, Ameren Missouri’s current plan for compliance with existing air emission regulations includes burning low-sulfur coal and installing new or optimizing existing air pollution control equipment. The actual amount of capital expenditures required to comply with existing environmental regulations may vary substantially from the above ~~estimate~~estimates because of uncertainty as to ~~whether~~future permitting requirements by state regulators and the EPA, ~~will substantially revise~~revisions to regulatory obligations, ~~exactly which~~and varying cost of potential compliance strategies, ~~will be used and their ultimate cost,~~ among other things.

The following sections describe the more significant environmental laws and rules and environmental enforcement and remediation matters that affect or could affect our operations. The EPA has initiated an administrative review of several regulations and ~~rulemaking activities,~~proposed amendments to regulations and guidelines, including to the ~~effluent limitation guidelines and the CCR rule,~~CSAPR, which could ultimately result in the revision of all or part of such rules.

In ~~2015,~~June 2022, the ~~EPA issued the Clean Power Plan, which would have established CO~~₂ ~~emissions standards applicable to existing power plants. The~~ United States Supreme Court ~~stayed the rule~~issued its decision in ~~February 2016, pending various legal challenges. In October 2017, the~~West Virginia v. EPA, ~~announced a proposal to repeal the Clean Power Plan. In December 2017, the EPA issued an advanced notice of proposed rulemaking to solicit input from stakeholders as to~~clarifying that there are limits on how the EPA ~~should~~may regulate CO₂ ~~emissions~~greenhouse gases absent further direction from ~~existing~~the United States Congress. The court concluded that emission caps

In January 2011, the United States Department of Justice, on behalf of the EPA, filed a complaint against Ameren Missouri in the United States District Court for the Eastern District of ~~Missouri. The complaint, as amended in October 2013, alleged~~Missouri alleging that ~~in performing~~ projects ~~at its Rush Island coal-fired energy center~~performed in 2007 and 2010 ~~Ameren Missouri~~at the coal-fired Rush Island Energy Center violated provisions of the Clean Air Act and Missouri law. ~~The litigation has been divided into two phases: liability and remedy.~~ In January 2017, the district court issued a liability ruling that the projects violated provisions of the Clean Air Act and Missouri law. The case then proceeded to the second phase to determine the actions required to remedy the violations found in the liability phase. The EPA previously withdrew all claims for penalties and fines. No date has been set by the district court for a trial on the remedy phase of the litigation. At the conclusion of both phases of the litigation,against Ameren Missouri ~~intends~~and, in September 2019, entered a remedy order that required Ameren Missouri to install a flue gas desulfurization system at the Rush Island Energy Center and a dry sorbent injection system at the Labadie Energy Center. Following an appeal ~~the liability ruling to~~from Ameren Missouri in August 2021, the United States Court of Appeals for the Eighth ~~Circuit.~~Circuit affirmed the liability ruling and the district court’s remedy order as it related to the installation of a flue gas desulfurization system at the Rush Island Energy Center, but reversed the order as it related to the installation of a dry sorbent injection system at the Labadie Energy Center. In November 2021, the court of appeals issued an order denying requests for re-consideration sought by both Ameren Missouri and the United States Department of Justice.

Based on its assessment of available legal, operational and regulatory alternatives, Ameren Missouri filed a motion in December 2021 with the district court to modify the remedy order to allow the retirement of the Rush Island Energy Center in advance of its previously expected useful life in lieu of installing a flue gas desulfurization system. The March 31, 2024 compliance date contained in the district court’s September 2019 remedy order remains in effect unless extended by the district court. In July 2022, in response to an Ameren Missouri request for a final, binding reliability assessment, the MISO designated the Rush Island Energy Center as a system support resource and concluded that certain mitigation measures, including transmission upgrades, should occur before the energy center is retired. The transmission upgrade projects have been approved by the MISO, and design and procurement activities necessary to complete the upgrades are underway. Ameren Missouri expects to complete the upgrades by mid-2025. In October 2022, the FERC approved a system support resource agreement, which became effective retroactively as of September 1, 2022. The agreement details the manner of continued operation for a system support resource that results in operating during peak demand times and emergencies. The system support resource designation and the related agreement are subject to annual renewal and revision. In September 2022, the Rush Island Energy Center began operating consistent with the system support resource agreement. In addition, in October 2022, the FERC established hearing and settlement procedures in response to an August 2022 request from Ameren Missouri for recovery of non-energy costs under the related MISO tariff. The FERC is under no deadline to issue an order related to this proceeding. Revenues and costs under the MISO tariff are expected to be included in the FAC. The district court has the authority to determine the retirement date and operating parameters for the Rush Island Energy Center and is not bound by the MISO determination of the Rush Island Energy Center as a system support resource or the FERC’s approval. The district court is under no deadline to issue a ruling modifying the remedy order. Related to this matter, in February 2022, the MoPSC issued an order directing the MoPSC staff to review the planned accelerated retirement of the Rush Island Energy Center. See Note 2 – Rate and Regulatory Matters for additional information.

In connection with the planned accelerated retirement of the Rush Island Energy Center, Ameren Missouri expects to seek approval from the MoPSC to finance the costs associated with the retirement, including the remaining unrecovered net plant balance associated with the facility, through the issuance of securitized utility tariff bonds pursuant to Missouri’s securitization statute. As such, Ameren Missouri did not request a change in the depreciation rates related to the Rush Island Energy Center in the electric regulatory rate review filed in August 2022. See Note 2 – Rate and Regulatory Matters for additional information on the August 2022 electric regulatory rate review. As of December 31, 2022 and 2021, the Rush Island Energy Center had a net plant balance of approximately $0.6 billion included in plant to be abandoned, net, within “Property, Plant, and Equipment, Net” and a rate base of approximately $0.4 billion. See Note 1 – Summary of Significant Accounting Policies for additional information regarding plant to be abandoned, net. In addition, Ameren Missouri filed a 2022 Change to the 2020 IRP with the MoPSC in June 2022 to reflect, among other things, the planned acceleration of the retirement of the Rush Island Energy Center from 2039, the retirement year for the facility as reflected in the 2020 IRP and reflected in depreciation rates approved by the December 2021 MoPSC electric rate order.

Ameren Missouri is unable to predict the ultimate resolution of this ~~matter~~matter; however, such resolution could have a material adverse effect on the results of operations, financial position, and liquidity of Ameren and Ameren Missouri. Among other things and subject to economic and regulatory considerations, resolution of this matter could result in increased capital expenditures for the installation of pollution control equipment, as well as increased operations and maintenance expenses. We are unable to predict the ultimate resolution of this matter or the costs that might be incurred.

~~In 2014,~~The EPA’s regulations implementing Section 316(b) of the ~~EPA issued its final rule applicable~~Clean Water Act require power plant operators to evaluate cooling water intake structures ~~at existing power plants. The rule requires a case-by-case evaluation~~ and ~~plan~~identify measures for reducing the number of aquatic organisms impinged on ~~the facility’s~~a power plant’s cooling water intake screens or entrained through the plant’s cooling water system. All of Ameren Missouri’s coal-fired and nuclear energy centers are subject to the cooling water intake structures rule. ~~The~~Requirements of the rule ~~will be~~are implemented ~~during~~by state regulators through the permit renewal process of

~~Additionally, in~~In 2015, the EPA issued a rule to revise the effluent limitation guidelines applicable to steam electric generating units. These guidelines established national standards for water discharges, ~~that are based on the effectiveness of available control technology. The EPA’s 2015 rule prohibits~~prohibit effluent discharges of certain waste streams, and ~~imposes~~impose more stringent limitations on certain water discharges from power ~~plants. In September 2017, the EPA published a rule that postponed the compliance dates~~plants by ~~two years for the limitations applicable to two specific waste streams so that it could potentially revise those standards.~~

Ameren and Ameren Missouri have AROs of ~~$150~~$49 million recorded on their respective balance sheets as of December 31, ~~2017,~~2022, associated with CCR storage ~~facilities that reflect the regulations issued in 2015.~~facilities. Ameren ~~plans to close these CCR storage facilities between 2018 and 2024. Ameren~~ Missouri ~~also~~ estimates it will need to make capital expenditures of ~~$300~~$30 million to ~~$350~~$50 million from ~~2018~~2023 through ~~2022~~2024 to implement its CCR management compliance ~~plan.~~plan, which includes installation of groundwater monitoring equipment and groundwater treatment facilities.

The Ameren Companies are involved in a number of remediation actions to clean up sites ~~affected~~impacted by the use or disposal of materials containing hazardous substances. Federal and state laws can require responsible parties to fund remediation regardless of their degree of fault, the legality of original disposal, or the ownership of a disposal site. ~~Ameren Missouri and Ameren Illinois have each been identified by federal or state governments as a potentially responsible party at several contaminated sites.~~

As of December 31, ~~2017,~~2022, Ameren Illinois ~~owned or was otherwise responsible for~~has remediated the majority of the 44 former MGP sites in Illinois ~~which are in various stages of investigation, evaluation, remediation,~~ and ~~closure. Ameren Illinois estimates it~~ could substantially conclude remediation efforts at the remaining sites by 2023. The ICC allows Ameren Illinois to recover such remediation and related litigation costs from its electric and natural gas utility customers through environmental cost ~~riders. Costs~~riders that are subject to annual prudence ~~review~~reviews by the ICC. As of December 31, ~~2017,~~2022, Ameren Illinois estimated the remaining obligation related to these former MGP sites at ~~$175~~$63 million to ~~$249~~$145 million. Ameren and Ameren Illinois recorded a liability of ~~$175~~$63 million to represent the estimated minimum obligation for these sites, as no other amount within the range was a better estimate. About half of the remaining liability recorded relates to remediation activities that are expected to be completed after 2023.

The scope of the remediation activities at these former MGP sites may increase as remediation efforts continue. Considerable uncertainty remains in these estimates because many site-specific factors can influence the ~~ultimate~~ actual costs, including unanticipated underground structures, the degree to which groundwater is encountered, regulatory changes, local ordinances, and site accessibility. The actual costs and timing of completion may vary substantially from these estimates.

Ameren Missouri participated in the investigation of various sites known as Sauget Area 2 located in Sauget, Illinois. In 2000, the EPA notified Ameren Missouri and numerous other companies that former landfills and lagoons at those sites may contain soil and groundwater contamination. In 2013, the EPA issued its record of decision for Sauget Area 2 approving the investigation and the remediation actions recommended by the potentially responsible parties. Further negotiation among the potentially responsible parties will determine how to fund the implementation of the EPA-approved cleanup remedies. As of December 31, 2017 and 2016, Ameren Missouri estimated its obligation related to Sauget Area 2 at $1 million to $2.5 million. Ameren Missouri recorded a liability of $1 million to represent its estimated minimum obligation for this site, as no other amount within the range was a better estimate.

Restricted cash included in “Other current assets” primarily represents funds held by an irrevocable Voluntary Employee Beneficiary Association (VEBA) trust, which provides health care benefits for active employees. Restricted cash included in “Other assets” on Ameren’s and Ameren Illinois’ balance sheets primarily represents amounts collected under a cost recovery rider restricted for use in the procurement of renewable energy credits and amounts in a trust fund restricted for the use of funding certain asbestos-related claims.

“Accounts receivable – trade” on Ameren’s and Ameren Illinois’ balance sheets include certain receivables purchased at a discount from alternative retail electric suppliers that elect to participate in the utility consolidated billing program. At December 31, 2022 and 2021, “Other current liabilities” on Ameren’s and Ameren Illinois’ balance sheets included payables for purchased receivables of $31 million and $27 million, respectively.

The following table provides a reconciliation of the beginning and ending amount of the allowance for doubtful accounts for the years ended December 31, 2022 and 2021:

As of December 31, 2022, accounts receivable balances that were 30 days or greater past due or that were a part of a deferred payment arrangement represented 17%, 14%, and 20%, or $107 million, $35 million, and $71 million, of Ameren’s, Ameren Missouri’s, and Ameren Illinois’ customer trade receivables before allowance for doubtful accounts, respectively. In comparison, as of December 31, 2021, these percentages were 20%, 17%, and 24%, or $94 million, $34 million, and $60 million, for Ameren, Ameren Missouri, and Ameren Illinois, respectively.

The following table presents the components of inventories for each of the Ameren Companies at December 31, 2022 and 2021:

The following table provides a reconciliation of the beginning and ending carrying amount of AROs for the years ended December 31, 2022 and 2021:

As of December 31, 2022 and 2021, Ameren’s noncontrolling interests included the preferred stock of Ameren Missouri and Ameren Illinois.

As of December 31, 2022, and 2021, the present value of benefits to be paid for deferred compensation obligations was $87 million and $91 million, respectively, which was primarily reflected in “Other deferred credits and liabilities” on Ameren’s consolidated balance sheet.

Ameren Missouri ~~Municipal Taxes~~

The following table presents the ~~court issued a final order approving a settlement agreement between Ameren Missouri~~average rate that was applied to eligible construction work in progress and the ~~municipalities.~~amounts of allowance for funds used during construction capitalized in 2022, 2021, and 2020:

Earnings per basic and diluted share are computed by dividing “Net Income Attributable to Ameren Common Shareholders” by the weighted-average number of basic and diluted common shares outstanding, respectively, during the applicable period. The ~~settlement agreement requires Ameren Missouri~~weighted-average shares outstanding for earnings per diluted share includes the incremental effects resulting from performance share units, restricted stock units, and forward sale agreements relating to ~~make payments representing certain tax receipts~~common stock when the impact would be dilutive, as calculated using the treasury stock method. For information regarding performance share units and restricted stock units, see Note 11 – Stock-based Compensation. For information regarding forward sale agreements, see Note 5 – Long-term Debt and Equity Financings.

The following table reconciles the weighted-average number of common shares outstanding to the ~~municipalities during~~diluted weighted-average number of common shares outstanding for the ~~first quarter~~years ended December 31, 2022, 2021, and 2020:

Capital expenditures at Ameren and Ameren Missouri ~~recorded immaterial current liabilities on their respective balance sheets as~~included wind generation expenditures of $525 million and $564 million for the years ended December 31, ~~2017, to represent~~2021 and 2020, respectively.

The following table provides noncash financing and investing activity excluded from the ~~payments made in February 2018 under~~statements of cash flows for the ~~settlement agreement.~~years ended December 31, 2022, 2021, and 2020:

Ameren has four segments: Ameren Missouri, Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Transmission. The Ameren Missouri segment includes all of the operations of Ameren Missouri. Ameren Illinois Electric Distribution consists of the electric distribution business of Ameren Illinois. Ameren Illinois Natural Gas consists of the natural gas business of Ameren Illinois. Ameren Transmission is primarily ~~composed~~consists of the aggregated electric transmission businesses of Ameren Illinois and ATXI. The category called Other primarily includes Ameren ~~parent company~~(parent) activities and Ameren Services.

Ameren Missouri has one segment. Ameren Illinois has three segments: Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Illinois Transmission. See Note 1 – Summary of Significant Accounting Policies for additional information regarding the operations of Ameren Missouri, Ameren Illinois, and ATXI.

Segment operating revenues and a majority of operating expenses are directly recognized and incurred by Ameren Illinois to each Ameren Illinois segment. Common operating expenses, miscellaneous income and expenses, interest charges, and income tax expense are allocated by Ameren Illinois to each Ameren Illinois segment based on certain factors, which primarily relate to the nature of the cost. Additionally, Ameren Illinois Transmission earns revenue from transmission service provided to Ameren Illinois Electric Distribution, other retail electric suppliers, and wholesale customers. The transmission expense for Illinois customers who have elected to purchase their power from Ameren Illinois is recovered through a cost recovery mechanism with no net effect on Ameren Illinois Electric Distribution earnings, as costs are offset by corresponding revenues. Transmission revenues from these transactions are reflected in Ameren Transmission’s and Ameren Illinois Transmission’s operating revenues. An intersegment elimination at Ameren and Ameren Illinois occurs to eliminate these transmission revenues and expenses.

The following tables present ~~revenues,~~information about the reported revenue and specified items reflected in net income attributable to common shareholders and capital expenditures by segment at Ameren and Ameren Illinois for the years ended December 31, ~~2017~~, ~~2016~~,2022, 2021, and ~~2015~~.2020. Ameren, Ameren Missouri, and Ameren Illinois management review segment capital expenditure information rather than any individual or total asset amount.

As of December 31, ~~2017,~~2022, evaluations were performed under the supervision and with the participation of management, including the principal executive officer and the principal financial officer of each of the Ameren Companies, of the effectiveness of the design and operation of such registrant’s disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) of the Exchange Act). Based on those evaluations, as of December 31, ~~2017,~~2022, the principal executive officer and the principal financial officer of each of the Ameren Companies concluded that such disclosure controls and procedures are effective to provide assurance that information required to be disclosed in such registrant’s reports filed or submitted under the Exchange Act is recorded, processed, summarized, and reported within the time periods specified in the SEC’s rules and forms, and that such information is accumulated and communicated to its management, including its principal executive and principal financial officers, to allow timely decisions regarding required disclosure.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness into future periods are subject to the risk that internal controls might become inadequate because of changes in conditions, and to the risk that the degree of compliance with the policies or procedures might deteriorate.

There has been no change in the Ameren Companies’ internal control over financial reporting during their most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, their internal control over financial reporting.

The Ameren Companies have no information reportable under this item that was required to be disclosed in a report on SEC Form 8-K during the fourth quarter of ~~2017~~2022 that has not previously been ~~reported on an SEC Form 8-K.~~reported.

Not Applicable.

Information required by Items 401, 405, 406 and 407(c)(3),(d)(4) and (d)(5) of SEC Regulation S-K for Ameren will be included in its definitive proxy statement for its ~~2018~~2023 annual meeting of shareholders filed pursuant to SEC Regulation 14A; it is incorporated herein by reference. Information required by these SEC Regulation S-K items for Ameren Missouri and Ameren Illinois will be included in each company’s definitive information statement for its ~~2018~~2023 annual meeting of shareholders filed pursuant to SEC Regulation 14C; it is incorporated herein by reference. Specifically, reference is made to the following sections of Ameren’s definitive proxy statement and to each of Ameren Missouri’s and Ameren Illinois’ definitive information statements: “Information Concerning Nominees to the Board of Directors,” “Section 16(a) ~~Beneficial Ownership Reporting Compliance,~~Reports,” “Corporate Governance” and “Board Structure.”

Information concerning executive officers of the Ameren Companies required by Item 401 of SEC Regulation S-K is reported under a separate caption entitled ~~“Executive Officers of the Registrants”~~“Information about our Executive Officers” in Part I of this report.

Ameren Missouri and Ameren Illinois do not have separately designated standing audit committees, but instead use Ameren’s ~~audit~~Audit and ~~risk committee~~Risk Committee to perform such committee functions for their boards of directors. These companies do not have securities listed on the NYSE and therefore are not subject to the NYSE listing standards. ~~Walter~~ J. ~~Galvin~~Edward Coleman serves as chairman of Ameren’s ~~audit~~Audit and ~~risk committee~~Risk Committee and Catherine S. Brune, ~~J. Edward Coleman,~~Ward H. Dickson, Noelle K. Eder, and ~~Ellen M. Fitzsimmons~~Leo S. Mackay, Jr. serve as members. The board of directors of Ameren has determined that ~~Walter J. Galvin and~~ J. Edward Coleman and Ward H. Dickson each qualify as an audit committee financial expert and that each is “independent” as that term is used in SEC Regulation 14A.

Also, on the same basis as reported above, the boards of directors of Ameren Missouri and Ameren Illinois use the ~~nominating~~Nominating and ~~corporate governance committee~~Corporate Governance Committee of Ameren’s board of directors to perform such committee functions. This ~~committee~~Committee is responsible for the nomination of directors and for corporate governance practices. Ameren’s ~~nominating~~Nominating and ~~corporate governance committee~~Corporate Governance Committee will consider director nominations from shareholders in accordance with its Director Nomination Policy, ~~Regarding Nominations of Directors,~~ which can be found on Ameren’s website: ~~www.ameren.com~~.www.amereninvestors.com.

To encourage ethical conduct in its financial management and reporting, Ameren has adopted a code of ethics that applies to the directors, officers, and employees of the Ameren Companies. Ameren has also adopted a supplemental code of ethics that applies to the principal executive officer, the president, the principal financial officer, the principal accounting officer, the controller, and the treasurer of ~~each of~~ the Ameren Companies. ~~Ameren has also adopted a code of business conduct that applies to the directors, officers, and employees of the Ameren Companies. It is referred to as the Principles of Business Conduct.~~ The Ameren Companies make available free of charge through Ameren’s website (~~www.ameren.com~~)(www.amereninvestors.com) the ~~Code~~code of ~~Ethics~~ethics and the ~~Principles~~supplemental code of ~~Business Conduct.~~ethics. Any amendment to the ~~Code~~code of ~~Ethics~~ethics or the ~~Principles~~supplemental code of ~~Business Conduct~~ethics and any waiver from a provision of the ~~Code~~code of ~~Ethics~~ethics or the ~~Principles~~supplemental code of ~~Business Conduct~~ethics as it relates to the principal executive officer, the president, the principal financial officer, the principal accounting officer, the controller, or the treasurer of each of the Ameren Companies will be posted on Ameren’s website within four business days following the date of the amendment or waiver.

Information required by Items 402 and 407(e)(4) and (e)(5) of SEC Regulation S-K for Ameren will be included in its definitive proxy statement for its ~~2018~~2023 annual meeting of shareholders filed pursuant to SEC Regulation 14A; it is incorporated herein by reference. Information required by these SEC Regulation S-K items for Ameren Missouri and Ameren Illinois will be included in each company’s definitive information statement for its ~~2018~~2023 annual meeting of shareholders filed pursuant to SEC Regulation 14C; it is incorporated herein by reference. Specifically, reference is made to the following sections of Ameren’s definitive proxy statement and to each of Ameren

The following table presents information as of December 31, ~~2017,~~2022, with respect to the shares of Ameren’s common stock that may be issued under its existing equity compensation ~~plans.~~plans:

Ameren Missouri and Ameren Illinois do not have separate equity compensation plans.

The information required by Item 403 of SEC Regulation S-K for Ameren will be included in its definitive proxy statement for its ~~2018~~2023 annual meeting of shareholders filed pursuant to SEC Regulation 14A; it is incorporated herein by reference. Information required by this SEC Regulation S-K item for Ameren Missouri and Ameren Illinois will be included in each company’s definitive information statement for its ~~2018~~2023 annual meeting of shareholders filed pursuant to SEC Regulation 14C; it is incorporated herein by reference. Specifically, reference is made to the following section of Ameren’s definitive proxy statement and each of Ameren Missouri’s and Ameren Illinois’ definitive information statement: “Security Ownership.”

Information required by Items 404 and 407(a) of SEC Regulation S-K for Ameren will be included in its definitive proxy statement for its ~~2018~~2023 annual meeting of shareholders filed pursuant to SEC Regulation 14A; it is incorporated herein by reference. Information required by these SEC Regulation S-K items for Ameren Missouri and Ameren Illinois will be included in each company’s definitive information statement for its ~~2018~~2023 annual meeting of shareholders filed pursuant to SEC Regulation 14C; it is incorporated herein by reference. Specifically, reference is made to the following sections of Ameren’s definitive proxy statement and to each of Ameren Missouri’s and Ameren Illinois’ definitive information statements: ~~“Policy and Procedures With Respect to Related~~“Related Person ~~Transactions”~~Transactions Policy” and “Director Independence.”

Information required by Item 9(e) of SEC Schedule 14A for the Ameren Companies will be included in the definitive proxy statement of Ameren and the definitive information statements of Ameren Missouri and Ameren Illinois for their ~~2018~~2023 annual meetings of shareholders filed pursuant to SEC Regulations 14A and 14C, respectively; it is incorporated herein by reference. Specifically, reference is made to the following section of Ameren’s definitive proxy statement and each of Ameren Missouri’s and Ameren Illinois’ definitive information statement: ~~“Independent~~“Selection of Independent Registered Public Accounting Firm.”

Ameren Corporation (parent company only) is a public utility holding company that conducts substantially all of its business operations through its subsidiaries. Ameren Corporation (parent company only) has accounted for its subsidiaries using the equity method. These financial statements are presented on a condensed basis.

See Note 1 – Summary of Significant Accounting Policies under Part II, Item 8, of this report for additional information.

See Note 131 – ~~Related-party Transactions~~Summary of Significant Accounting Policies under Part II, Item 8, of this report for ~~information on the tax allocation agreement between Ameren Corporation (parent company only) and its subsidiaries.~~additional information.

Ameren, Ameren Services, and other non-state-regulated Ameren subsidiaries have the ability, subject to Ameren parent company and applicable regulatory short-term borrowing authorizations, to access funding from the Credit Agreements and the commercial paper programs through a non-state-regulated subsidiary money pool agreement. All participants may borrow from or lend to the non-state-regulated money pool. The total amount available to pool participants from the non-state-regulated subsidiary money pool at any given time is reduced by the

See Note 4 – Short-term Debt and Liquidity under Part II, Item 8, of this report for a description and details of short-term debt and liquidity needs of Ameren Corporation (parent company only).

See Note 5 – Long-term Debt and Equity Financings under Part II, Item 8, of this report for additional information on Ameren Corporation’s (parent company only) long-term debt, indenture provisions, forward sale agreements related to common stock, and ~~restricted cash balance.~~ATM program.

See Note 14 – Commitments and Contingencies under Part II, Item 8, of this report for a description of all material contingencies of Ameren Corporation (parent company only).

~~See Note 12 –~~The following table presents the components of “Total Other Expense, Net” in the Condensed Statement of Income ~~Taxes under Part II, Item 8, of this report~~and Comprehensive Income for ~~information regarding~~ the ~~impacts of the TCJA on Ameren Corporation (parent company only).~~years ended December 31, 2022, 2021, and 2020:

The Ameren Companies elected not to provide a summary of the Form 10-K.

The documents listed below are being filed or have previously been filed on behalf of the Ameren Companies and are incorporated herein by reference from the documents indicated and made a part hereof. Exhibits not identified as previously filed are filed herewith:

The file number references for the Ameren Companies’ filings with the SEC are: Ameren, 1-14756; Ameren Missouri, 1-2967; and Ameren Illinois, 1-3672.

*Compensatory plan or arrangement.

Each registrant hereby undertakes to furnish to the SEC upon request a copy of any long-term debt instrument not listed above that such registrant has not filed as an exhibit pursuant to the exemption provided by Item 601(b)(4)(iii)(A) of Regulation S-K.


☐
		OR

~~( )~~		Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to .



Commission File Number	Exact name of registrant as specified in its charter; State of Incorporation; Address and Telephone Number		IRS Employer Identification No.

1-14756	Ameren Corporation	43-1723446

	~~43-1723446~~
1-2967				~~(Missouri Corporation)~~
		~~1901 Chouteau Avenue~~
		~~St. Louis, Missouri 63103~~
		~~(314) 621-3222~~

~~1-2967~~		Union Electric Company	43-0559760

	~~43-0559760~~
1-3672			~~(Missouri Corporation)~~
		~~1901 Chouteau Avenue~~
		~~St. Louis, Missouri 63103~~
		~~(314) 621-3222~~

~~1-3672~~		Ameren Illinois Company	37-0211380
		~~(Illinois Corporation)~~
		~~6 Executive Drive~~
		~~Collinsville, Illinois 62234~~



~~Registrant~~	Title of each class	Trading Symbol(s)	Name of each exchange on which registered
~~Ameren Corporation~~	Common Stock, $0.01 par value per share	AEE	New York Stock Exchange



~~(X)~~	☒	Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the fiscal year ended December 31, ~~2017.~~2022



Registrant						Title of each class
Union Electric Company						Preferred Stock, cumulative, no par value, stated value $100 per share
Ameren Illinois Company						Preferred Stock, cumulative, $100 par value ~~per share~~ ~~Depositary Shares, each representing one-fourth of a share of 6.625% Preferred Stock, cumulative, $100 par value per share~~



~~Ameren Corporation~~		ý
~~Union Electric Company~~		ý
~~Ameren Illinois Company~~		ý



Registrant		Title of each class of common stock		Shares
Ameren Corporation		Common stock, $0.01 par value per ~~share: 242,634,798~~share		262,028,768

Union Electric Company	Common stock, $5 par value per share, held by Ameren Corporation ~~(parent company of the registrant):~~		102,123,834

Ameren Illinois Company	Common stock, no par value, held by Ameren Corporation ~~(parent company of the registrant):~~		25,452,373



				Page
GLOSSARY OF TERMS AND ABBREVIATIONS					1
~~Forward-looking Statements~~FORWARD-LOOKING STATEMENTS					4
PART I
Item 1.			Business		56
			General		56
			Business Segments		67
			Rates and Regulation		7
			Transmission		119
			Supply of Electric Power		1110
			Power Generation		1211
			Renewable Energy and Zero Emission Standards		12
			Customer Energy-Efficiency Programs		13
			Natural Gas Supply for Distribution		14
			Human Capital Management		14
			Industry Issues		1416
			Operating Statistics		1618
			Available Information		1820
Item 1A.			Risk Factors		1820
Item 1B.			Unresolved Staff Comments		2631
Item 2.			Properties		2731
Item 3.			Legal Proceedings		2833
Item 4.			Mine Safety Disclosures		2834
Information about Our Executive Officers ~~of the Registrants (Item 401(b) of Regulation S-K)~~					2934

PART II
Item 5.			Market for Registrants’ Common Equity, Related Stockholder Matters, and Issuer Purchase of Equity Securities		3136
Item 6.			~~Selected Financial Data~~(Reserved)		3337
Item 7.			Management’s Discussion and Analysis of Financial Condition and Results of Operations		3437
			Overview		3438
			Results of Operations		3542
			Liquidity and Capital Resources		5057
			Outlook		6267
			Regulatory Matters		6674
			Accounting Matters		6774
Item 7A.			~~Effects of Inflation and Changing Prices~~		69
~~Item 7A.~~	Quantitative and Qualitative Disclosures About Market Risk	7078
Item 8.			Financial Statements and Supplementary Data		7482
			Ameren Corporation		7888
			Union Electric		8392
			Ameren Illinois		8796
			Note 1. Summary of Significant Accounting Policies		91100
			Note 2. Rate and Regulatory Matters		98104
			Note 3. Property, Plant, and Equipment, Net		~~104~~116
			Note 4. Short-term Debt and Liquidity		~~105~~117
			Note 5. Long-term Debt and Equity Financings		~~107~~120
			Note 6. Other Income, ~~and Expenses~~Net		~~113~~127
			Note 7. Derivative Financial Instruments		~~113~~127
			Note 8. Fair Value Measurements		~~116~~129
			Note 9. Callaway Energy Center		~~122~~133
			Note 10. Retirement Benefits		~~124~~136
			Note 11. Stock-based Compensation		~~132~~142
			Note 12. Income Taxes		~~133~~144
			Note 13. Related-party Transactions		~~137~~147
			Note 14. Commitments and Contingencies		~~140~~150
			Note 15. ~~Segment~~Supplemental Information		~~144~~154
			~~Selected Quarterly~~Note 16. Segment Information		~~146~~157

Item 9.			Changes in and Disagreements with Accountants on Accounting and Financial Disclosure		~~147~~161
Item 9A.			Controls and Procedures		~~147~~162
Item 9B.			Other Information		~~148~~162
Item 9C.			Disclosure Regarding Foreign Jurisdictions that Prevent Inspections		162
~~PART III~~
PART III
Item 10.			Directors, Executive Officers, and Corporate Governance		~~148~~162
Item 11.			Executive Compensation		~~148~~163
Item 12.			Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters		~~149~~163
Item 13.			Certain Relationships and Related Transactions and Director Independence		~~149~~164
Item 14.			Principal ~~Accounting~~Accountant Fees and Services		~~149~~164

PART IV
Item 15.			Exhibits and Financial Statement Schedules		~~150~~165
Item 16.			Form 10-K Summary		~~155~~170
EXHIBIT INDEX					~~156~~171
SIGNATURES					~~163~~178



~~Ameren Missouri~~	~~3,639~~
~~Ameren Illinois~~	~~3,423~~
~~Ameren Services~~	~~1,553~~
~~Ameren~~	~~8,615~~


~~(a)~~	~~Ameren Transmission segment includes associated Ameren (parent) interest charges, Ameren Transmission Company, LLC, ATX East, LLC, and ATX Southwest, LLC.~~



	Rate Regulator	Allowed Return on Equity	Percent of Common Equity	Rate Base (in billions)	Portion of Ameren’s 2017 Operating Revenues^(a)
Ameren Missouri
Electric service^(b)	MoPSC	9.2% - 9.7%^(c)	(c)	(c)	54%
Natural gas delivery service	MoPSC	(d)	(d)	(d)	2%
Ameren Illinois
Electric distribution delivery service^(e)	ICC	8.40%	50.0%	$2.7	25%
Natural gas delivery service^(f)	ICC	9.60%	50.0%	$1.2	12%
Electric transmission service^(g)	FERC	10.82%	51.6%	$1.6	4%
ATXI
Electric transmission service^(g)	FERC	10.82%	56.2%	$1.3	3%


~~(a)~~	Includes pass-through costs recovered from customers, such as purchased power for electric distribution delivery service and natural gas purchased for resale for natural gas delivery service, and intercompany eliminations.


~~(b)~~	~~Ameren Missouri’s electric generation, transmission, and delivery service rates are bundled together and charged to retail customers under a combined electric service rate.~~


~~ITEM 1.~~	~~BUSINESS~~


•Safety and security •Commitment to excellence •Respect •Accountability			•Diversity, equity, and inclusion •Integrity •Teamwork •Stewardship


	Collective Bargaining Unit	Female(a)	Racially and/or Ethnically Diverse(a)
Ameren	47%	24%	16%
Ameren Missouri	59%	17%	14%
Ameren Illinois	55%	23%	13%
Ameren Services	11%	40%	23%


~~(c)~~	Based on the MoPSC’s March 2017 rate order. This rate order specified that an implicit return on equity was within a range of 9.2% to 9.7%. The rate order did not specify a percent of common equity or rate base. The return on equity used for allowance for equity funds used during construction is 9.53%.


~~(d)~~	Based on the MoPSC’s January 2011 rate order. This rate order did not specify the allowed return on equity, the percent of common equity, or rate base. It includes the impacts on rate base and operating revenues relating to the ISRS for investments after the January 2011 rate order.


~~(f)~~	~~Based on the ICC’s December 2015 rate order. The rate order was based on a 2016 future test year.~~


•We Care about our customers, our communities, and each other •We Serve with Passion			•We Deliver for our customers and stakeholders, today and tomorrow •We WinTogether as a result of our teamwork and collaboration


	Employee Count	Average Tenure (in years)	Attrition Rate
Ameren	9,244	13	8%
Ameren Missouri	4,039	14	7%
Ameren Illinois	3,243	13	8%
Ameren Services	1,962	11	10%


Generation Description	Ameren	Ameren Missouri	Ameren Illinois	Ameren Services
Baby Boomer (birth years between 1946 and 1964)	17%	18%	16%	17%
Generation X (birth years between 1965 and 1980)	41%	40%	40%	43%
Millennials (birth years between 1981 and 1996)	38%	37%	40%	37%
Generation Z/Post Millennial (birth years after 1997)	4%	5%	4%	3%


•	~~complex new and proposed environmental laws, regulations, and requirements, including air and water quality standards, mercury emissions standards, CCR management requirements, and potential CO~~₂ ~~limitations, which may reduce the frequency at which electric generating units are dispatched based upon their CO~~₂~~emissions;~~


Electric Operating Statistics – Year Ended December 31,	2022		2021		2020
Electric Sales – kilowatthours (in millions):
Ameren Missouri:
Residential	13,915		13,366		13,267
Commercial	13,826		13,556		13,117
Industrial	4,090		4,151		4,158
Street lighting and public authority	76		81		88
Ameren Missouri retail load subtotal	31,907		31,154		30,630
Off-system sales	7,645		7,425		7,578
Ameren Missouri total	39,552		38,579		38,208
Ameren Illinois Electric Distribution(a):
Residential	11,708		11,620		11,491
Commercial	11,867		11,795		11,414
Industrial	10,981		11,076		10,674
Street lighting and public authority	410		430		442
Ameren Illinois Electric Distribution total	34,966		34,921		34,021
Eliminate affiliate sales	(190)		(412)		(322)
Ameren total	74,328		73,088		71,907
Electric Operating Revenues (in millions):
Ameren Missouri:
Residential	$	1,578	$	1,445	$	1,373
Commercial	1,219		1,126		1,025
Industrial	290		280		261
Other, including street lighting and public authority	171		170		155
Ameren Missouri retail load subtotal	$	3,258	$	3,021	$	2,814
Off-system sales and capacity	591		191		170
Ameren Missouri total	$	3,849	$	3,212	$	2,984
Ameren Illinois Electric Distribution:
Residential	$	1,325	$	933	$	867
Commercial	768		545		486
Industrial	199		135		124
Other, including street lighting and public authority	(36)		26		21
Ameren Illinois Electric Distribution total	$	2,256	$	1,639	$	1,498
Ameren Transmission:
Ameren Illinois Transmission(b)	$	424	$	365	$	329
ATXI	192		199		194
Eliminate affiliate revenues	(1)		(2)		—
Ameren Transmission total	$	615	$	562	$	523
Other and intersegment eliminations	(139)		(116)		(94)
Ameren total	$	6,581	$	5,297	$	4,911



Electric Operating Statistics – Year Ended December 31,	2017			2016			2015
Electric Sales – kilowatthours (in millions):
Ameren Missouri:
Residential	12,653			13,245			12,903
Commercial	14,384			14,712			14,574
Industrial	4,469			4,790			8,273
Street lighting and public authority	117			125			126
Ameren Missouri retail load subtotal	31,623			32,872			35,876
Off-system	10,640			7,125			7,380
Ameren Missouri total	42,263			39,997			43,256
Ameren Illinois Electric Distribution^(a):
Residential	10,985			11,512			11,554
Commercial	12,382			12,583			12,280
Industrial	11,359			11,738			11,863
Street lighting and public authority	515			521			524
Ameren Illinois Electric Distribution total	35,241			36,354			36,221
Eliminate affiliate sales	(440		)	(520		)	(385		)
Ameren total	77,064			75,831			79,092
Electric Operating Revenues (in millions):
Ameren Missouri:
Residential	$	1,416		$	1,421		$	1,464
Commercial	1,207			1,223			1,258
Industrial	305			315			469
Other, including street lighting and public authority	115			102			84
Ameren Missouri retail load subtotal	$	3,043		$	3,061		$	3,275
Off-system	370			333			195
Ameren Missouri total	$	3,413		$	3,394		$	3,470
Ameren Illinois Electric Distribution:
Residential	$	870		$	894		$	858
Commercial	527			518			474
Industrial	113			96			124
Other, including street lighting and public authority	58			41			76
Ameren Illinois Electric Distribution total	$	1,568		$	1,549		$	1,532
Ameren Transmission:
Ameren Illinois Transmission^(b)	$	258		$	232		$	189
ATXI	168			123			70
Ameren Transmission total	$	426		$	355		$	259
Other and intersegment eliminations	(97		)	(102		)	(81		)
Ameren total	$	5,310		$	5,196		$	5,180


~~(a)~~	Sales for which power was supplied by Ameren Illinois as well as alternative retail electric suppliers. In 2017, 2016, and 2015, Ameren Illinois procured power on behalf of its customers for 23%, 23%, and 26%, respectively, of its total kilowatthour sales.


~~(b)~~	~~Includes $42 million, $45 million, and $38 million in 2017, 2016, and 2015, respectively, of electric operating revenues from transmission services provided to Ameren Illinois Electric Distribution.~~


Natural Gas Operating Statistics – Year Ended December 31,	2022		2021		2020
Natural Gas Sales – dekatherms (in millions):
Ameren Missouri:
Residential	8		7		7
Commercial	4		4		3
Industrial	1		1		1
Transport	9		9		9
Ameren Missouri total	22		21		20
Ameren Illinois Natural Gas:
Residential	59		54		55
Commercial	18		16		15
Industrial	6		4		7
Transport	99		100		96
Ameren Illinois Natural Gas total	182		174		173
Ameren total	204		195		193
Natural Gas Operating Revenues (in millions):
Ameren Missouri:
Residential	$	119	$	79	$	76
Commercial	56		34		29
Industrial	7		4		4
Transport and other	15		24		16
Ameren Missouri total	$	197	$	141	$	125
Ameren Illinois Natural Gas:
Residential	$	846	$	657	$	541
Commercial	221		172		136
Industrial	41		35		14
Transport and other	72		93		69
Ameren Illinois Natural Gas total	$	1,180	$	957	$	760
Other and intercompany eliminations	(1)		(1)		(2)
Ameren total	$	1,376	$	1,097	$	883

Rate Base Statistics – At December 31,	2022		2021		2020
Rate Base (in billions):
Electric transmission and distribution	$	15.4	$	13.5	$	12.1
Natural gas transmission and distribution	2.9		2.7		2.4
Coal generation:
Labadie Energy Center	0.9		0.9		0.9
Sioux Energy Center	0.7		0.7		0.7
Rush Island Energy Center	0.4		0.4		0.4
Meramec Energy Center (retired in December 2022)	—		0.1		0.1
Coal generation total	2.0		2.1		2.1
Nuclear generation	1.5		1.5		1.5
Renewable generation (hydroelectric, wind, solar, methane gas)	1.5		1.5		1.0
Natural gas generation	0.3		0.3		0.3
Rate base total	$	23.6	$	21.6	$	19.4



Primary Fuel Source			Energy Center	Location		Net Kilowatt Capability^(a)
~~Coal~~Ameren Missouri:			~~Labadie~~
Coal			Labadie(b)	Franklin County, Missouri		2,372,000
			Rush Island(c)	Jefferson County, Missouri		1,178,000
			Sioux(d)	St. Charles County, Missouri		972,000
Total coal						4,522,000
Nuclear			~~Meramec~~^(b)Callaway(f)	Callaway County, Missouri		1,194,000
Hydroelectric			Osage(f)	Lakeside, Missouri		235,000
			Keokuk	Keokuk, Iowa		148,000
Total hydroelectric						383,000
Pumped-storage			Taum Sauk(f)	Reynolds County, Missouri		440,000
Wind			High Prairie Renewable	Adair and Schuyler Counties, Missouri		400,000
			Atchison Renewable	Atchison County, Missouri		298,800
Total wind						698,800
Natural gas (CTs)			Audrain(g)	Audrain County, Missouri		608,000
			Venice(h)	Venice, Illinois		489,000
			Goose Creek(h)	Piatt County, Illinois		438,000
			Pinckneyville(h)	Pinckneyville, Illinois		316,000
			Raccoon Creek(h)	Clay County, Illinois		304,000
			Kinmundy(h)	Kinmundy, Illinois		210,000
			Peno Creek(g)	Bowling Green, Missouri		172,000
Total natural gas						2,537,000
Oil (CTs)			Fairgrounds(e)	Jefferson City, Missouri		55,000
			Mexico(e)	Mexico, Missouri		54,000
			Moberly(e)	Moberly, Missouri		54,000
			Moreau(e)	Jefferson City, Missouri		54,000
Total oil						217,000
Methane gas (CT)			Maryland Heights	Maryland Heights, Missouri		9,000
Solar			Montgomery County	Montgomery County, Missouri		5,700
			O’Fallon	O’Fallon, Missouri		4,500
			BJC	St. Louis, Missouri		1,600
			Cape Girardeau	Cape Girardeau, Missouri		1,200
			Lambert	St. Louis County, Missouri		~~591,000~~900
~~Total coal~~			South St. Louis	St. Louis, Missouri		~~5,113,000~~200
~~Nuclear~~Total solar			~~Callaway~~	~~Callaway County, Missouri~~		~~1,194,000~~14,100
~~Hydroelectric~~Total Ameren Missouri			~~Osage~~	~~Lakeside, Missouri~~		~~240,000~~10,014,900
Ameren Illinois:			~~Keokuk~~	~~Keokuk, Iowa~~	~~144,000~~
~~Total hydroelectric~~			~~384,000~~
~~Pumped-storage~~	~~Taum Sauk~~	~~Reynolds County, Missouri~~	~~440,000~~
~~Oil (CTs)~~	~~Fairgrounds~~	~~Jefferson City, Missouri~~	~~55,000~~
	~~Meramec~~	~~St. Louis County, Missouri~~	~~55,000~~
	~~Mexico~~	~~Mexico, Missouri~~	~~54,000~~
	~~Moberly~~	~~Moberly, Missouri~~	~~54,000~~
	~~Moreau~~	~~Jefferson City, Missouri~~	~~54,000~~
~~Total oil~~			~~272,000~~
~~Natural gas (CTs)~~	~~Audrain~~^(c)	~~Audrain County, Missouri~~	~~608,000~~
	~~Venice~~^(d)	~~Venice, Illinois~~	~~491,000~~
	~~Goose Creek~~	~~Piatt County, Illinois~~	~~438,000~~
	~~Pinckneyville~~	~~Pinckneyville, Illinois~~	~~316,000~~
	~~Raccoon Creek~~	~~Clay County, Illinois~~	~~304,000~~
	~~Meramec~~^(b)(d)(e)	~~St. Louis County, Missouri~~	~~281,000~~
	~~Kinmundy~~^(d)	~~Kinmundy, Illinois~~	~~208,000~~
	~~Peno Creek~~^(c)(d)	~~Bowling Green, Missouri~~	~~192,000~~
~~Total natural gas~~			~~2,838,000~~
~~Methane gas (CT)~~	~~Maryland Heights~~	~~Maryland Heights, Missouri~~	~~8,000~~
~~Solar~~	~~O’Fallon~~	~~O’Fallon, Missouri~~	~~3,000~~
~~Total Ameren and Ameren Missouri~~			~~10,252,000~~


~~(a)~~Solar			~~Net kilowatt capability is the generating capacity available for dispatch from the energy center into the electric transmission grid.~~East St. Louis

East St. Louis, Illinois			2,500
~~(b)~~Total Ameren			~~All coal-fueled kilowatts and 236,000 natural-gas-fueled kilowatts at the Meramec energy center are scheduled for retirement in 2022.~~


~~(c)~~		~~There are economic development lease arrangements applicable to these CTs.~~

10,017,400
~~(d)~~	~~These CTs have the capability to operate on either oil or natural gas (dual fuel).~~


	Ameren Missouri		Ameren Illinois
Circuit miles of electric transmission lines(a)	3,126		4,716
Circuit miles of electric distribution lines	33,846		45,972
Percentage of circuit miles of electric distribution lines underground	24	%	16	%
Miles of natural gas transmission and distribution mains	3,509		18,680
Underground natural gas storage fields	—		12
Total working capacity of underground natural gas storage fields in billion cubic feet	—		24


~~(a)~~	~~ATXI owns 303 miles of transmission lines not reflected in this table.~~


~~ITEM 5.~~	~~MARKET FOR REGISTRANTS’ COMMON EQUITY, RELATED STOCKHOLDER MATTERS, AND ISSUER PURCHASE OF EQUITY SECURITIES~~