UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

For the Fiscal Year Ended December 31, 20202023

OR

For the transition period from to

Commission File Number: 1-12252 (Equity Residential)

Commission File Number: 0-24920 (ERP Operating Limited Partnership)

EQUITY RESIDENTIAL

ERP OPERATING LIMITED PARTNERSHIP

(Exact name of registrant as specified in its charter)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:

None (Equity Residential)

Units of Limited Partnership Interest (ERP Operating Limited Partnership)

(Title of each class)

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act).

The aggregate market value of Common Shares held by non-affiliates of the Registrant was approximately $21.7$25.0 billion based upon the closing price on June 30, 20202023 of $58.82$65.97 using beneficial ownership of shares rules adopted pursuant to Section 13 of the Securities Exchange Act of 1934 to exclude voting shares owned by Trustees and Executive Officers, some of whom may not be held to be affiliates upon judicial determination.

The number of Common Shares of Beneficial Interest, $0.01 par value, outstanding on February 12, 20218, 2024 was 372,663,215.379,553,591.

DOCUMENTS INCORPORATED BY REFERENCE

EXPLANATORY NOTE

This report combines the annual reports on Form 10-K for the year ended December 31, 20202023 of Equity Residential and ERP Operating Limited Partnership. Unless stated otherwise or the context otherwise requires, references to “EQR” mean Equity Residential, a Maryland real estate investment trust (“REIT”), and references to “ERPOP” mean ERP Operating Limited Partnership, an Illinois limited partnership. References to the “Company,” “we,” “us” or “our” mean collectively EQR, ERPOP and those entities/subsidiaries owned or controlled by EQR and/or ERPOP. References to the “Operating Partnership” mean collectively ERPOP and those entities/subsidiaries owned or controlled by ERPOP. The following chart illustrates the Company’s and the Operating Partnership’s corporate structure:

EQR is the general partner of, and as of December 31, 20202023 owned an approximate 96.4%97.0% ownership interest in, ERPOP. The remaining 3.6%3.0% interest is owned by limited partners. As the sole general partner of ERPOP, EQR has exclusive control of ERPOP’s day-to-day management. Management operates the Company and the Operating Partnership as one business. The management of EQR consists of the same members as the management of ERPOP.

The Company is structured as an umbrella partnership REIT (“UPREIT”) and EQR contributes all net proceeds from its various equity offerings to ERPOP. In return for those contributions, EQR receives a number of OP Units (see definition below) in ERPOP equal to the number of Common Shares it has issued in the equity offering. The Company may acquire properties in transactions that include the issuance of OP Units as consideration for the acquired properties. Such transactions may, in certain circumstances, enable the sellers to defer in whole or in part, the recognition of taxable income or gain that might otherwise result from the sales. This is one of the reasons why the Company is structured in the manner shown above. Based on the terms of ERPOP’s partnership agreement, OP Units can be exchanged with Common Shares on a one-for-one basis because the Company maintains a one-for-one relationship between the OP Units of ERPOP issued to EQR and the outstanding Common Shares.

The Company believes that combining the reports on Form 10-K of EQR and ERPOP into this single report provides the following benefits:

The Company believes it is important to understand the few differences between EQR and ERPOP in the context of how EQR and ERPOP operate as a consolidated company. All of the Company’s property ownership, development and related business operations are conducted through the Operating Partnership and EQR has no material assets or liabilities other than its investment in ERPOP. EQR’s primary function is acting as the general partner of ERPOP. EQR also issues equity from time to time, the net proceeds of which it is obligated to contribute to ERPOP. EQR does not have any indebtedness as all debt is incurred by the Operating Partnership. The Operating Partnership holds substantially all of the assets of the Company, including the Company’s ownership interests in its joint ventures. The Operating Partnership conducts the operations of the business and is structured as a partnership with no publicly traded equity. Except for the net proceeds from equity offerings by EQR (which are contributed to the capital of ERPOP in exchange for additional partnership interests in ERPOP (“OP Units”) (on a one-for-one Common Share per OP Unit basis) or additional preference units in ERPOP (on a one-for-one preferred share per preference unit basis)), the Operating Partnership generates all remaining capital required by the Company’s business. These sources include the Operating Partnership’s working capital, net cash provided by operating activities, borrowings under its revolving credit facility and/or commercial paper program, the issuance of secured and unsecured debt and partnership interests, and proceeds received from disposition of certain properties and joint venture interests.

Shareholders’ equity, partners’ capital and noncontrolling interests are the main areas of difference between the consolidated financial statements of the Company and those of the Operating Partnership. The limited partners of the Operating Partnership are accounted for as partners’ capital in the Operating Partnership’s financial statements and as noncontrolling interests in the Company’s financial statements. The noncontrolling interests in the Operating Partnership’s financial statements include the interests of unaffiliated partners in various consolidated partnerships. The noncontrolling interests in the Company’s financial statements include the same noncontrolling interests at the Operating Partnership level and limited partner OP Unit holders of the Operating Partnership. The differences between shareholders’ equity and partners’ capital result from differences in the equity issued at the Company and Operating Partnership levels.

To help investors understand the differences between the Company and the Operating Partnership, this report provides separate consolidated financial statements for the Company and the Operating Partnership; a single set of consolidated notes to such financial statements that includes separate discussions of each entity’s debt, noncontrolling interests and shareholders’ equity or partners’ capital, as applicable; and a combined Management’s Discussion and Analysis of Financial Condition and Results of Operations section that includes discrete information related to each entity.

This report also includes separate Part II, Item 9A, Controls and Procedures, sections and separate Exhibits 31 and 32 certifications for each of the Company and the Operating Partnership in order to establish that the requisite certifications have been made and that the Company and the Operating Partnership are compliant with Rule 13a-15 or Rule 15d-15 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and 18 U.S.C. §1350.

In order to highlight the differences between the Company and the Operating Partnership, the separate sections in this report for the Company and the Operating Partnership specifically refer to the Company and the Operating Partnership. In the sections that combine disclosure of the Company and the Operating Partnership, this report refers to actions or holdings as being actions or holdings of the Company. Although the Operating Partnership is generally the entity that directly or indirectly enters into contracts and joint ventures and holds assets and debt, reference to the Company is appropriate because the Company is one business and the Company operates that business through the Operating Partnership.

As general partner with control of ERPOP, EQR consolidates ERPOP for financial reporting purposes, and EQR essentially has no assets or liabilities other than its investment in ERPOP. Therefore, the assets and liabilities of the Company and the Operating Partnership are the same on their respective financial statements. The separate discussions of the Company and the Operating Partnership in this report should be read in conjunction with each other to understand the results of the Company on a consolidated basis and how management operates the Company.

EQUITY RESIDENTIAL

ERP OPERATING LIMITED PARTNERSHIP

TABLE OF CONTENTS

PART I

Item 1. Business

General

Equity Residential (“EQR”) is committed to creating communities where people thrive. The Company, a member of the S&P 500, is focused on the acquisition, development and management of residential properties located in and around dynamic cities that attract high qualityaffluent long-term renters. ERP Operating Limited Partnership (“ERPOP”) is focused on conducting the multifamily property business of EQR. EQR is a Maryland real estate investment trust (“REIT”) formed in March 1993 and ERPOP is an Illinois limited partnership formed in May 1993. References to the “Company,” “we,” “us” or “our” mean collectively EQR, ERPOP and those entities/subsidiaries owned or controlled by EQR and/or ERPOP. References to the “Operating Partnership” mean collectively ERPOP and those entities/subsidiaries owned or controlled by ERPOP.

EQR is the general partner of, and as of December 31, 20202023 owned an approximate 96.4%97.0% ownership interest in, ERPOP. All of the Company’s property ownership, development and related business operations are conducted through the Operating Partnership and EQR has no material assets or liabilities other than its investment in ERPOP. EQR issues equity from time to time, the net proceeds of which it is obligated to contribute to ERPOP, but does not have any indebtedness as all debt is incurred by the Operating Partnership. The Operating Partnership holds substantially all of the assets of the Company, including the Company’s ownership interests in its joint ventures. The Operating Partnership conducts the operations of the business and is structured as a partnership with no publicly traded equity.

The Company’s corporate headquarters is located in Chicago, Illinois and the Company also operates regional property management offices in eachmost of its markets.

On May 18, 2023, the Company announced that Samuel Zell, its Founder and Chairman of the Board of Trustees, had passed away earlier that same day. David J. Neithercut, the Company’s former Chief Executive Officer and a member of the Company’s Board of Trustees since 2006, has been appointed as Chairman.

Certain capitalized terms used herein are defined in the Notes to Consolidated Financial Statements.Statements or the Definitions section of Item 7, Management's Discussion and Analysis of Financial Condition and Results of Operations. See also Note 17 in the Notes to Consolidated Financial Statements for additional discussion regarding the Company’s segment disclosures.

Available Information

You may access our Annual Report on Form 10-K, our Quarterly Reports on Form 10-Q, our Current Reports on Form 8-K, our proxy statements and any amendments to any of those reports/statements we file with or furnish to the Securities and Exchange Commission (“SEC”) free of charge on our website, www.equityapartments.com.www.equityapartments.com. These reportsreports/statements are made available on our website as soon as reasonably practicable after we file them with or furnish them to the SEC. The information contained on our website, including any information referred to in this report as being available on our website, is not a part of or incorporated into this report.

Business Objectives and Operating and Investing Strategies

Overview

The Company is one of the largest U.S. publicly-traded owners and operators of high-qualityhigh quality rental apartment properties, with a portfolio primarily locatedan established presence in urban and dense suburban communities in and around Boston, New York, Washington, D.C., Southern California (including Los Angeles, Orange County and San Diego), San Francisco and Seattle, and Denver.  Ouran expanding presence in Denver, Atlanta, Dallas/Ft. Worth and Austin. Through our ownership in these markets, continuewe seek to be the primaryoptimize our portfolio by balancing risk and maximizing returns. We believe that this portfolio will allow us to produce more consistent cash flows in a volatile world where local market conditions may cause operating fundamentals to change rapidly. We believe our markets are knowledge centers of the U.S. economy drawing thethat draw employers and their talented affluent workers and employers that drive economic growth in the United States. OurWe believe the locations of our properties are located in places thatthese markets are attractive to these affluent knowledge workers whom(who often choose to rent for lifestyle reasons) that we hope to convert into satisfied long-term residents.

We believe we have created a best-in-classan industry-leading operating platform and balance sheet to run our properties. Our employees are focused on delivering remarkable customer service to our residents so they will stay with us longer, be willing to pay higher rent for a great experience and will tell others about how much they love living in an Equity Residential property. We utilize technology and other innovative methods of engagement with our residents to foster relationships and community, improve the resident experience and operate our business more efficiently. OurWe pair that with disciplined balance sheet management that enhances returns and value creation

while maintaining flexibility to take advantage of future opportunities. We believe that our stakeholders value stability, liquidity, predictability and accountability and that is the mission to which we remain unwaveringly committed.

6

Table of ContentsDespite overall economic concerns, demand to live in our apartment communities remains healthy and we believe that the long-term prospects for our business remain strong. Our business benefits from elevated single family home ownership costs, positive household formation trends and the overall deficit in housing across the country, especially in the areas in which we are investing. Our well-located communities provide an exceptional experience for our residents around dynamic cities that we believe will continue to attract affluent long-term renters.

Equity Residential is committed to creating communities where people thrive. We carry this, our corporate purpose, through our relationships with our customers, our employees, our shareholders and the communities in which we operate. It drives our commitmentcommitments to sustainability, diversity and inclusion, the total well-beingwellbeing of our employees and being a responsible corporate citizen in the communities in which we operate, which is especially relevant when we face unprecedented challenges like the novel coronavirus (“COVID-19”) pandemic.  operate.

Despite the challenges we have faced with the COVID-19 pandemic, we believe that the long-term prospects for our business remain strong.  Our well-located communities are in and around dynamic cities that we believe will continue to attract high quality long-term renters. When the pandemic subsides, we believe urban centers will re-energize and once again provide significant networking and other benefits for current and prospective residents who may have temporarily deferred, but not abandoned, their desire to live in vibrant major U.S. metropolitan areas.

Investment Strategy

The Company’s long-term strategy is to invest in apartment communitiesproperties located in strategically targeted markets with the goal of maximizing our risk-adjusted total returns by balancing current cash flow generation with long-term capital appreciation. We seek to meet this goal by investing in markets that are characterized by conditions favorable to multifamily property operations over the long-term. We also consider governmental fiscal health, political/regulatory riskOur multi-pronged investment strategy featuring acquisitions, new stand-alone and resiliencyexpansion developments, densifying developments and accretive renovations of existing properties is focused on optimizing and balancing our targetedportfolio in terms of location, including between our established and expansion markets and between urban and suburban submarkets within those markets. The markets we focus on generally feature one or more of the following characteristics that allow us to drive performance:

We believe our strategy capitalizes on the preference of renters of all ages to live in the locations where we operate thatwhich typically are near to transportation (both public transit and convenient highway access), entertainment, employment centers/universities and cultural and outdoor amenities. DemandFurthermore, we believe that demand for rental housing iswill continue to be driven primarily bythrough household formations from the Millennial segment and increasingly from theyounger segments of our population, particularly Generation Z, segmentwhile retaining Millennials for longer, and to a lesser extent, capturing the aging Baby Boomer generation.

Overall, our high-quality resident tendsThe Company continues to workallocate capital in the highest earning sectors of the economy and is not rent burdened, creating the abilityorder to raise rents more readily in good economic times and reducing risk during downturns.  Many of these workers are employed in the fields of Science, Technology, Engineering and Mathematics, or STEM jobs.  Theyoptimize performance by balancing current cash flow growth with long-term capital appreciation. We have experienced significantly lower job loss during COVID-19. Once it subsides, we believe we are extremely well positioneddone so by adding expansion markets to benefit for many years to come as a result of the significant impact the various generations discussed above will have on rental housing.  

Over the last decade, the Company has done an extensive repositioning of its portfolio into urban and highly walkable, close-in suburban assets.  While we continue to look for opportunities to expand our portfolio when certain submarkets in these locations, it is our intention over time to further diversify our portfolio into select newthose markets that sharemeet many of the same characteristics aslisted above. Expansion into these markets of Denver, Atlanta, Dallas/Ft. Worth and Austin includes investments in both urban and suburban properties in select submarkets and is generally being funded by reducing exposure to older or lower returning assets in selected established markets. Development also plays an important role in our current markets and to optimize the mix of our properties located in urban vs. dense suburban submarkets within our existing markets.

Operations and Innovation

We attempt to balance occupancy and rental rates to maximize our revenue while exercising tight cost control to generate the highest possible return to our shareholders.  Revenuecapital allocation. Development activity is maximized through our customized pricing system that uses market data on current and projected demand and availability to create both current and forward pricing daily for each apartment unit we manage.  We believe our success prior to the pandemic in renewing our residents is due to our focus on the resident experience.  This focus has driven the strong occupancy and renewal rate growth that we have achieved over the last several years prior to the COVID-19 pandemic, which we would expect to return once the pandemic subsides.

7

Table of Contents

Technology continues to drive innovation in the rental industry and to evolve at a rapid pace. We have been and continue to be a leader in deploying and investing in property technology to serve our customers better and operate more efficiently.  Having been a first mover in such important areas as revenue management and online leasing, we are focused on technology that improves our in-house pipeline and redevelopment of some existing operating marginsproperties and customer experience while also meeting the current needs of our customers, including addressing the challenges of the pandemic.  We use a standardized purchasing systemstrategic partnerships and joint-ventures with third-party developers in both established and expansion markets. The Company remains committed to control our operating expenses and a business intelligence platform that allows all our team members to quickly identify and address issues and opportunities.  Our operations benefitted from having many of these initiatives in place during the pandemic, allowing us to interact with our customers in a safe and responsible manner, including self-guided tours, automated responses to customer inquiries and enhanced service and maintenance management. While we believe areas such as “smart home” technology and others will provide the foundation for current and future improvements to how we do business, we will continue to consider the cost and longevity of technology capital investments versus the benefits.

Our Commitment to Environmental, Social and Governance (“ESG”)

At Equity Residential, we believe a focus on ESG is a key way to programmatically address stakeholder concerns as part of our corporate purpose.  This needs to be a sustainable endeavor, in which we provide properties that will stand the test of time and remain attractive to our customers and the community without negatively impacting the environment.  We have a dedicated in-house team that initiates and applies sustainable practices in all aspects of our business, including investment activities, development property operations and property management activities. Multifamily housing is one of the most environmentally-friendly uses of real estate, as each property provides homes for hundreds of families in a denser shared environment.  We consider building locations based on walkability, accessibility, neighborhoods and parks.  We also design our communities to support amenities such as fitness centers and we select locations near shops, healthy restaurants and health and wellness programs, enabling a low carbon footprint lifestyle for our residents to live, work and play.

Our sustainability goals help us focus efforts and drive outcomes to create a more sustainable future for all.  We are especially focused on energy consumption, water consumption and greenhouse gas emissions.  We invest in developing and renovating our properties, with a focus on reducing waste, energy and water use by investing in energy-saving technology, such as those for irrigation, lighting, HVAC and renewable energy, while positively impacting the experience of our residents and the value of our assets.

We are also intensely focused on the “Social” and “Governance” aspects of ESG.  As detailed below, we have a commitment to our employees’ engagement, diversity and wellness that is the foundation of our corporate purpose.  We also recognize that a successful company must incorporate the best corporate governance practices in order to better serve its stakeholders.  

In 2018, the Company became the first multifamily REIT ever to issue a “green bond”.  As a result, the net proceeds of approximately $396.7 million from the offering were allocated to eligible green/sustainable certified projects.  For additional information regarding our ESG efforts, see our November 2020 Environmental, Social and Governance Report at our website, www.equityapartments.com.  This report, which includes Sustainability Accounting Standards Board disclosures and incorporates recommendations from the Task Force on Climate-related Financial Disclosures, was reviewed and approved by the Corporate Governance Committee of our Board of Trustees, which monitors the Company’s ongoing ESG efforts.  We continue to enhance our ESG disclosure efforts, including auditing the results outlined in the above report.  Furthermore, our annual proxy statements contain additional information on our corporate governance practices. Such annual proxy statements and the information contained therein are not part of or incorporated into this report.

Human Capital

At Equity Residential, our team of approximately 2,600 employees is the driving force behind our success. We believe that our richly diverse work environment captures top talent, cultivates the best ideas and creates the widest possible platform for this success in line with our corporate purpose of “Creating communities where people thrive.” Our core principles, affectionately named “Ten Ways to Be a Winner,” guide our behavior as individuals and collectively as a team, helping usdriver of external growth but acknowledges its incremental risk, particularly in our goal to deliver market-leading performance.  As parthigher inflationary cost environments, when evaluating it as a method of our Ten Ways to Be a Winner, we encourage our team members to raise questions, take educated risks, offer new ideas and help us make the right decisions.  One way we live the “Ten Ways” is by enriching our culture through our core “Equity Values”—Diversity and Inclusion, Social Responsibility, Sustainability and Total Well-Being.  We have assembled an employee-led Equity Values Council to lead our efforts on these values by acting as change agents to drive initiatives, create goals and awareness, and encourage colleagues to participate in community service activities and wellness initiatives.  In addition, executive compensation is based, in part, on meeting important Equity Values goals, and our Board of Trustees takes an active role in overseeing our efforts in this regard.

8

Table of Contentsexpansion.

Diversity and InclusionCompetition

Pay Equity

Employee Engagement

9

Table of Contents

Training and Development

Health, Safety and Wellness

Competition

All of the Company’s properties are located in developed areas with multiple housing choices, including other multifamily properties. The number of competitive housing choices or multifamily properties in a particular area could have a material effect on the Company’s ability to lease apartment units at its properties and on the rents charged. The Company may be competing with other housing providers that have greater resources than the Company and whose managers have more experience than the Company’s managers. In addition, other forms of rental properties and single-familysingle family housing provide housing alternatives to potential residents of multifamily properties. See Item 1A, Risk Factors, for additional information with respect to competition.

Operations and Innovation

We attempt to balance occupancy and rental rates to maximize our revenue while exercising tight cost control to generate the highest possible cash flow generation to our shareholders. Our focus on operating efficiency and delivery of an exceptional resident living experience has driven strong Physical Occupancy and a high Percentage of Residents Renewing while achieving strong renewal rate growth.

We deliver this performance through rapidly evolving technology and innovation that is increasingly prevalent in our industry. We have been and continue to be a leader in deploying and investing in property technology to serve our customers better and operate more efficiently. Having a history as a first mover in such important areas as online leasing, we are focused on technology that drives superior margins and improves customer experience. We use a standardized purchasing system to control our operating expenses and a business intelligence platform and other data analytics that allow our team members to quickly identify and address issues and opportunities. Many of these initiatives allow us to interact with our customers in a safe, responsible and convenient manner, including self-guided tours, automated responses to customer inquiries and enhanced service and maintenance management. While we believe areas such as “smart home” technology and others will provide the foundation for current and future improvements to how we do business, we will continue to consider the cost and longevity of technology capital investments and their benefits.

Our Commitment to Corporate Responsibility

At Equity Residential, we believe focusing on corporate responsibility is a key way to programmatically address stakeholder concerns as part of our corporate purpose as we recognize the profound impact that the real estate industry can have on our environment and society as a whole. We strive to create and maintain a sustainable portfolio that not only has a low environmental footprint, but also one that is attractive to our customers and the community and resilient to the changing climate. We apply best practices for sustainability across all aspects of our real estate business. We have a dedicated in-house team that initiates and applies sustainable practices in all aspects of our business, including investment activities, development, property operations and property management activities. Multifamily housing is one of the most environmentally-friendly uses of real estate, as each property provides homes for hundreds of families in a denser shared environment. We consider building locations based on walkability, accessibility, neighborhoods and communities. Our properties support amenities such as fitness centers and we select locations near shops, restaurants, outdoor amenities such as bike/running paths and health clubs, enabling a low carbon footprint lifestyle for our residents to live, work and play.

Equity Residential’s sustainability program actively manages environmental impacts and climate-related risks and opportunities through optimized, financially responsible capital investments and technologies. We methodically focus on energy, water, waste and emissions to advance the program’s policies, targets and resilience outcomes as well as our shareholders' long-term financial interests. Together, we believe our program drives long-term asset value, responsibly manages risks and engages our communities, residents, employees and shareholders as part of our broader sustainability strategy and commitment to good corporate citizenship and maximizing investment performance. Our expertise has shown that as real estate owners, developers and managers, we have the ability to make a positive impact on the environment while also enhancing our financial performance and strengthening our organization’s sense of purpose.

To further strengthen our commitments to sustainability initiatives, we set ambitious targets to reduce our environmental impact across the portfolio aligned with global climate change initiatives. For example, we recently set a science-based target to reduce our absolute Scope 1, 2, and 3 greenhouse gas emissions (from our two biggest categories) by 30% by 2030 from a 2018 base year. We continue to enhance our environmental disclosure efforts by calculating and disclosing our Scope 3 emissions.

We also issued two sustainable fixed-income instruments (each a “green bond”) designed to support projects that contribute to environmental sustainability, becoming the first multifamily REIT to ever issue a green bond. The Company also has a $10.0 million investment in a fund focused on early stage sustainability and climate change mitigation technology relevant to the built environment.

As detailed below, we have a commitment to our employees’ engagement, diversity and inclusion and wellness that serves as the foundation of our corporate purpose. We celebrate differences and are committed to cultivating an inclusive environment of belonging for all employees, driving excellence through shared perspectives and collaborative innovation. We also recognize that a successful company must incorporate the best corporate governance practices in order to better serve its stakeholders. Consistent with the Company's purpose and commitment to the incorporation of corporate responsibility concepts in all aspects of its business, executive compensation includes a goal which focuses on environmental, social and governance factors.

For additional information regarding our corporate responsibility efforts, see our 2023 Environmental, Social and Governance Report at our website, www.equityapartments.com, which includes third-party limited assurance covering some of the environmental metrics included in the report. The report, which includes Sustainability Accounting Standards Board disclosures and incorporates recommendations from the Task Force on Climate-Related Financial Disclosures, was reviewed and approved by the Corporate Governance Committee of our Board of Trustees, which monitors the Company’s ongoing corporate responsibility efforts. The Environmental, Social and Governance Report is not part of or incorporated into this report. Furthermore, our annual proxy statements contain additional information on our corporate responsibility efforts, including detailed information regarding our corporate governance practices. Such annual proxy statements and the information contained therein are not part of nor incorporated into this report, except as otherwise provided herein.

Human Capital

At Equity Residential, our team of approximately 2,400 employees is the driving force of our success. We believe that our richly diverse work environment captures top talent, cultivates the best ideas and creates the widest possible platform for this success in line with our corporate purpose of “Creating communities where people thrive”. Our core principles, affectionately named “Ten Ways to Be a Winner,” guide our behavior as individuals and collectively as a team, helping us in our goal to deliver market-leading performance. As part of our Ten Ways to Be a Winner, we encourage our team members to raise questions, take educated risks, offer new ideas and help us make the right decisions. One way we live the “Ten Ways” is by enriching our culture through our core “Equity Values," which include Diversity & Inclusion, Social Responsibility, Sustainability and Total Wellbeing. We have assembled the Equity Values Council, a diverse employee group reflective of the broader Company, to lead our efforts on these values by acting as change agents to drive initiatives, create goals and awareness, and encourage colleagues to participate in community service activities and wellness initiatives.

Diversity and Inclusion

Pay Equity

Employee Engagement

Training and Development

Health, Safety and Wellness

Regulatory Considerations

See Item 1A, Risk Factors, for information concerning the potential effects of governmental regulations, including environmental regulations, on our operations.

Item 1A. Risk Factors

General

This Item 1A includes forward-looking statements. You should refer to our discussion of the qualifications and limitations on forward-looking statements included in Item 7, Management’s Discussion and Analysis of Financial Condition and Results of Operations.

The occurrence of the events discussed in the following risk factors could adversely affect, possibly in a material manner, our business, financial condition or results of operations, which could affect the value of our common shares of beneficial interest or preferred shares of beneficial interest (which we refer to collectively as “Shares”), Preference Units, OP Units, restricted units and our public unsecured debt. In this section, we refer to the Shares, Preference Units, OP Units, restricted units and public unsecured debt together as our “securities” and the investors who own such securities as our “security holders.”

Risks Related to the COVID-19 Pandemic

The ongoing COVID-19 pandemic and measures intended to prevent its spread could have a material adverse effect on our business, results of operations, cash flows and financial condition.

In March 2020, the World Health Organization declared COVID-19 a pandemic.  The outbreak has led governments and other authorities around the world, including federal, state and local authorities in the United States, to impose measures intended to control its spread, including restrictions on movement and business operations such as travel bans, border closings, business closures, quarantines, social distancing and shelter-in-place orders.  The COVID-19 pandemic has also caused, and may likely continue to cause, severe economic, market and other disruptions worldwide.  There can be no assurance that conditions will not continue to deteriorate as a result of the pandemic.

The impact of the COVID-19 pandemic and measures to prevent its spread could materially negatively impact our business, results of operations, financial condition and liquidity in a number of ways, including:

11

Table of Contents

The extent of the COVID-19 pandemic’s effect on our operational and financial performance will depend on future developments including the duration, spread and intensity of the outbreak and the rollout and effectiveness of vaccines, all of which are uncertain and difficult to predict.  To the extent the COVID-19 pandemic adversely affects our business, results of operations, cash flows and financial condition, it may also have the effect of heightening many of the other risks described below.  Due to the speed with which the situation is continuing to develop, we are not able at this time to estimate the effect of these factors on our business, but the adverse impact on our business, results of operations, cash flows and financial condition could be material.

Risks Related to our Business Strategy

Investing in real estate is inherently subject to risks that could negatively impact our business.

Investing in real estate is subject to varying degrees and types of risk. While we seek to mitigate these risks through various strategies, including geographic diversification, market research and proactive asset management, among other techniques, these risks cannot be eliminated.eliminated entirely. Factors that may impact cash flows and real estate values include, but are not limited to:

12

Table of Contents

The geographic concentration of our properties could have an adverse effect on our operations.

TheWhile the Company continues to diversify its portfolio with the addition of the expansion markets, the Company’s properties are still predominantly concentrated in our primarilyestablished coastal markets (generally within certain dense urban and located in and around dynamic cities that we believe attract high quality long-term renters.

suburban submarkets). If one or more of ourthese markets is unfavorably impacted by specific geopolitical and/or economic conditions, local real estate conditions, increases in social unrest, increases in real estate and other taxes, reduced quality of life, deterioration of local or state government health, rent control or rent stabilization laws, other similar regulations, or localized environmental and climate issues, or natural/man-made disasters, the impact of such conditions may have a more negative impact on our results of operations than if our properties were more geographically diverse.

Within its primarily coastal markets, the Company is also concentrated in certain dense urban and suburban submarkets.  To Additionally, to the extent that these markets or submarkets within these markets become less desirable to operate in, including changes in multifamily housing supply and demand, our results of operations could be more negatively impacted than if we were more diversified within our markets or invested in a greater number of markets.

For example, the urban core submarkets of New York City, San Francisco, CA and Boston, MA, have been more adversely impacted by the COVID-19 pandemic in comparison to our other markets. Due to our concentrations in these submarkets, we have experienced larger decreases in rental income from elevated rent concessions and lower occupancy than we might have otherwise.

Failure to generate sufficient revenue could limit our ability to make financing payments or distributions to security holders.

A decrease in cash flows due to declines in rental revenue could negatively affect our ability to make financing payments and distributions to our security holders. Significant expenditures associated with each property, such as real estate taxes, insurance, utilities, maintenance costs and employee wages and benefits, may also negatively impact cash flows, and these expenditures may not decline as quickly or at the same rate as revenues when circumstances might cause a reduction of those revenues at our properties.

Competition in multifamilyfor housing may negatively affect operations and demand for the Company’s properties or residents.

Our properties face competition for residents from other existing or new multifamily properties, condominiums, single family homes and other living arrangements, whether owned or rental, that may attract residents from our properties or prospective residents that would otherwise choose to live with us. As a result, we may not be able to renew existing resident leases or enter into new resident leases, or if we are able to renew or enter into new leases, they may be at rates or terms that are less favorable than our current rates or terms, resulting in a material impact on our results of operations.

Additionally, our properties face competition for residents as a result of innovations in technology innovation.and amenities. Therefore, we may not be able to retain residents or attract new residents if we are unable to identify and cost effectively implement new, relevant technologiestechnologies/amenities and to keep up with constantly changing resident demand for the latest innovations.  innovations in these areas.

The short-term nature of apartment leases exposes us more quickly to the effects of declining market rents, potentially making our revenueresults of operations and cash flows more volatile.

Generally, our residential apartment leases are for twelve months or less. If the terms of the renewal or relettingreleasing are less favorable than current terms, then the Company’s results of operations and financial condition could be negatively affected. Given our generally shorter-term lease structure, our rental revenues are impacted by declines in market rents more quickly than if our leases were for longer terms. In addition, operating expenses associated with each property, such as real estate taxes, insurance, utilities, maintenance costs and employee wages and benefits, may not decline at all or decline at the same rate as revenues when circumstances might cause a reduction of those revenues at our properties.

Because real estate investments are illiquid, we may not be able to sell properties when appropriate.

Real estate investments often cannot be sold quickly due to regulatory constraints, market conditions or otherwise. As a result, we may not be able to reconfigure our portfolio, including the diversification of our portfolio into the expansion markets, as promptly as desired or as quickly in response to changing economic or other conditions. We may also be unable to consummate dispositions in a timely manner, on attractive terms, or at all. The capitalization rates/disposition yields at which properties may be sold could also be higher than historic rates, thereby reducing our potential proceeds from sale. In some cases, we may also determine that we will not recover the carrying amount of the property upon disposition, potentially causing an impairment charge. This inability to reallocate our capital promptly could negatively affect our financial condition, including our ability to make distributions to our security holders.

Competition for acquisitions may prevent us from acquiring properties on favorable terms.

We may not be successful in pursuing acquisition and development opportunities. We expect that other real estate investors will compete with us for attractive investment opportunities or may also develop properties in markets where we focus our development and acquisition efforts. We may not be in a position or have the opportunity in the future to make suitable property acquisitions on favorable terms.

Operations from new acquisitions, development projects and renovations may fail to perform as expected.

We intend to actively acquire, develop and renovate multifamily operating properties as part of our business strategy. Newly acquired, developed or renovated properties may not perform as we expect. We may also overestimate the revenue (or underestimate the expenses) that athese new or repositioned projectproperties may generate. The occupancy rates and rentsrental rates at these properties may also fail to meet our expectations for these investments. Land parcels acquired for development may lose significant value prior to the expectations underlying our investment.start of construction. Development and renovations are subject to even greater uncertainties and risks due to the complexities and lead time in estimating costs.  We may underestimate the costs necessary to operate an acquired property to the

13

Table of Contents

standards established for its intended market position.build or complete these projects. We may also underestimate the costs to complete a development property or to complete a renovation.

Additionally, we have and may in the future acquire large portfolios of properties or companies that could increase our size and result in alterations to our capital structure. We may be unable to integrate the operations of newly acquired large portfolios or companies and realize the anticipated synergies and other benefits or do so within the anticipated time frame.

Furthermore, we have in the past and may in the future decide to invest in expansion markets outside of our existing established markets by acquiring and/or developing properties in accordance with the Company's long-term investment strategy. Our historical experience in our established markets does not ensure that we will be able to operate successfully in new markets, should we choose to enter them. Entering into new markets may expose us to a variety of risks, including an inability to accurately evaluate local market conditions and local economies, to identify appropriate acquisition and/or development opportunities, to hire and retain key personnel and a lack of familiarity with local governmental regulations.

Construction risks on our development projects could affect our profitability.

We intend to continue to develop multifamily properties through both wholly owned and joint venture arrangements as part of our business strategy. Development often includes long planning and entitlement timelines, subjecting the projectprojects to changes in market conditions. It can involve complex and costly activities, including significant environmental remediation or construction work in our markets. We have experienced and may alsocontinue to experience an increase in costs due to general disruptions that affect the cost of labor and/or materials, such as supply chain disruptions, trade disputes, tariffs, labor unrest, and/geopolitical conflicts or geopolitical conflicts.other factors that create inflationary pressures. We may abandon opportunities that we have already begun to explore for a number of reasons, and as a result, we may fail to recover expenses or option paymentscosts already incurred in exploring those opportunities. We may also be unable to obtain, or experience delays in obtaining, necessary zoning, occupancy, or other required governmental or third-party permits and authorizations. These and other risks inherent in development projects, including the joint venture risks noted below, could result in increased costs or the delay or abandonment of opportunities.

We are subject to risks involved in real estate activity through joint ventures.

We currently, and may continue to in the future, develop and acquire properties in joint ventures with unrelated third parties. Joint ventures create risks including the following:

At times we have entered into agreements providing for joint and several liability with our partners. We have in the past and may in the future choose to guarantee part of or all of certain joint venture debt or to act as a lender to the joint venture itself. We and our respective joint venture partners may each have the right to trigger a buy-sell arrangement that could cause us to sell our interest, or acquire our partner's interest, at a time or price that is unfavorable to us. Each joint venture agreement is individually negotiated and our ability to operate, finance or dispose of properties and interests in such joint ventures in our sole discretion may be limited to varying degrees depending on the terms of the applicable joint venture agreement. To the extent we have commitments to, on behalf of or are dependent on any such off-balance sheet commitments, or if those commitments or their properties or leases are subject to material contingencies, our liquidity and financial condition could be adversely affected.

In some instances, our joint venture partners may also have competing interests or objectives that could create conflicts of interest similar to those noted above. These objectives may be contrary to our compliance with the REIT requirements, and our REIT status could be jeopardized if any of our joint ventures do not operate in compliance with those requirements. To the extent our partners do not meet their obligations to us or our joint ventures, or they take actions inconsistent with the interests of the joint venture, it could have a negative effect on our results of operations and financial condition, including distributions to our security holders.

We are subject to risks involved in activity through real estate technology and other real estate fund investments.

We have entered into, and may continue in the future to enter into, real estate technology and other real estate fund investments. Noncontrolling interests and passive investments are illiquid,inherently risky because we have limited ability to influence business decisions. The managers of such investments have autonomy over the day-to-day operations of the business and may make business, financial or management decisions with which we do not agree or take risks or otherwise act in a manner that does not serve our interests. In addition, the market for the technologies or products these companies are developing are typically in the early stages and may not materialize to the expected scale, causing these companies to abandon, modify or alter their product, service or overall strategy. Further, there is no assurance that these companies can obtain additional capital or resources or generate sufficient cash flow to sustain operations and successfully execute their strategy. The performance of these investments may also rely on the services of a limited number of key individuals, the loss of whom could significantly adversely affect such investments’ performance. As a result, we may notrecognize an impairment of our investment or be ableunable to sell or otherwise monetize any of the investments we have acquired or may acquire in the future.

We are subject to risks related to our properties when appropriate.that are subject to ground leases.

Real estate investments generally cannot be sold quickly.We have entered into, and may continue in the future to enter into, long-term ground leases with respect to assets that may restrict our ability to finance, sell or otherwise transfer our interests in these properties, limit our use and expose us to loss of the properties if such agreements are breached by us or terminated. These restrictions may limit our ability to timely sell or exchange the properties, impair the properties’ value or negatively impact our ability to operate the properties. In addition, as we get closer to the lease termination dates, the values of the properties could decrease if we are unable to agree upon an extension of the lease with the lessor. Certain of these ground leases have payments subject to annual escalations and/or periodic fair market value adjustments which could adversely affect our financial condition or results of operations.

We face certain risks related to our Non-Residential operating activities.

The Non-Residential space (includes retail and public parking garage operations) at our properties primarily serves as an additional amenity for our residents and neighbors. The longer-term nature of our Non-Residential leases (generally five to ten years with market based renewal options) and the characteristics of many of our Non-Residential tenants (generally small, local businesses) may subject us to certain risks. We may not be able to reconfigurelease new space for rents that are consistent with our portfolio promptly in responseprojections or for market rates. Also, when leases for our existing Non-Residential space expire, the space may not be relet or the terms of reletting, including the cost of allowances and concessions to changing economic or other conditions.  Wetenants, may be unable to consummate such dispositions in a timely manner, on attractive terms, or at all.  In some cases, weless favorable than the current lease terms. The presence of competitive alternatives and other market conditions (including online shopping) may also determine that we will not recover the carrying amount of the property upon disposition.  This inability to reallocate our capital promptly could negatively affect our financial condition, including our ability to make distributionslease our Non-Residential space and impact the level of rents we can obtain. If our Non-Residential tenants experience financial distress or bankruptcy, they may fail to comply with their contractual obligations, seek concessions, such as rent abatements and deferrals, in order to continue operations or cease their operations, any or all of which could lead us to record a non-cash write-off of a tenant's straight-line rent receivable (like we did in 2023 due to the Rite Aid bankruptcy) and could adversely impact our security holders.results of operations and financial condition.

The Company’s real estate assets may be subject to impairment charges.

A decline in the fair value of our assets may require us to recognize an impairment against our assets under accounting principles generally accepted in the United States (“GAAP”) if we were to determine that, with respect to any assets in unrealized loss positions, we do not have the ability and intent to hold such assets for a period of time sufficient to allow for recovery of the depreciated cost of such assets. If such a determination were to be made, we would recognize unrealized losses through earnings and write-down the depreciated cost of such assets to a new cost basis, based on the fair value of such assets on the date they are considered to be impaired. Such impairment charges reflect non-cash losses at the time of recognition; subsequent disposition or sale of such assets could further affect our future losses or gains, as they are based on the difference between the sale price received and adjusted amortizeddepreciated cost of such assets at the time of sale. If we are required to recognize material asset impairment charges, in the future, these charges could adversely affect our financial condition and results of operations.

We are subject to risks involved in real estate activity through joint ventures.

We currently, and may continue to in the future, develop and acquire properties in joint ventures with other persons or entities.  Joint ventures create risks including the following:

At times we have entered into agreements providing for joint and several liability with our partners.  We also have in the past and could choose in the future to guarantee part of or all of certain joint venture debt.  We and our respective joint venture partners may each have the right to trigger a buy-sell arrangement that could cause us to sell our interest, or acquire our partner's interest, at a time or price that is unfavorable to us.  In some instances, joint venture partners may also have competing interests or objectives that could create conflicts of interest similar to those noted above. These objectives may be contrary to our compliance with the REIT requirements, and our REIT status could be jeopardized if any of our joint ventures do not operate in compliance with those requirements. To the extent our partners do not meet their obligations to us or our joint ventures, or they take actions inconsistent with the interests of the joint venture, it could have a negative effect on our results of operations and financial condition, including distributions to our security holders.

14

Table of Contents

Corporate social responsibility, specifically related to ESG,sustainability efforts, may impose additional costs and expose us to new risks.

Sustainability, social and governanceCorporate responsibility evaluations remain highly important to some investors and other stakeholders. Certain organizations that provide corporate governance and other corporate risk advisory services to investors have developed scores and ratings to evaluate companies and investment funds based upon ESGcorporate responsibility metrics. Many investors focus on positive ESG-relatedcorporate responsibility-related business practices and scores when choosing to allocate their capital and may consider a company's score as a reputational or other factor in making an investment decision. Investors'Government regulators' and investors' increased focus and activism related to ESGcorporate responsibility and similar matters may constrain our business operations or increase expenses.expenses or capital expenditures. In addition, investors may decide to refrain from investing in us as a result of their assessment of our approach to and consideration of ESGcorporate responsibility factors. We may face reputational damage in the event our corporate responsibility procedures or standards do not meet the standards set by various constituencies. Although we have generally scored highly in these metrics to date, there can be no assurance that we will continue to score highly in the future. In addition, the criteria by which companies are rated for ESGtheir efforts may change, which could cause us to receive lower scores than in previous years. A low ESG scorerating could result in a negative perception of the Company, exclusion of our securities from consideration by certain investors who may elect to invest with our competition instead and/or cause investors to reallocate their capital away from the Company, all of which could have an adverse impact on the price of our securities.

Our various technology-related initiatives to improve our operating margins and customer experience may fail to perform as expected.

We have developed and may continue to develop initiatives that are intended to serve our customers better and operate more efficiently, including “smart home” technology and self-service options that are accessible to residents through smart devices or otherwise. Such initiatives have involved and may involve our employees having new or different responsibilities and processes with which they may be unfamiliar. We may incur significant costs and divert resources in connection with such initiatives, and these initiatives may not perform as expected, which could adversely affect our business, results of operations, cash flows and financial condition.​

Risks Related to our Financing Strategy and Capital Structure

Disruptions in the financial markets could hinder our ability to obtain debt and equity financing and impact our acquisitions and dispositions.

Dislocations and disruptions in capital markets could result in increased costs or lack of availability of debt financing (including under our commercial paper program) and equity financing. Such events may affect our ability to refinance existing debt, require us to

utilize higher cost alternatives and/or impair our ability to adjust to changing economic and business conditions. Capital market disruptions have and could continue to negatively impact our ability to make acquisitions or make it more difficult or not possible for us to sell properties or may unfavorably affect the price we receive for properties that we do sell. Such disruptions could cause the price of our securities to decline.

Changes in market conditions and volatility of share prices could decrease the market price of our Common Shares.

The stock markets, including the New York Stock Exchange on which we list our Common Shares, have experienced significant price and volume fluctuations over time.time, including in recent years. As a result, the market price of our Common Shares has been and could continue to be similarly volatile. Investors in our Common Shares consequently may experience a decrease in the value of their shares, including decreases due to this volatility and not necessarily related to our operating performance or prospects. Additionally, the market price of our Common Shares may decline or fluctuate significantly in response to the sale of substantial amounts of our Common Shares, or the anticipation of the sale of such shares, by large holders of our securities.securities, as well as our inclusion or exclusion from stock indices. The issuance of additional Common Shares by the Company, or the perception that such issuances might occur, could also cause significant volatility and decreases in the value of our shares. Continuing high interest rates can also negatively impact the value of our Common Shares, not just through higher interest expense on our debt, but also as investors and markets discount our earnings more and/or assume slower growth in earnings.

Our financial counterparties may not perform their obligations.

Although we have not experienced any material counterparty non-performance, disruptionsDisruptions in financial and credit markets or other events could impair the ability of our counterparties to perform under their contractual obligations to us. There are multiple financial institutions that are individually committed to provide borrowings under our revolving credit facility.facility and to pay us amounts due under various interest rate derivative agreements. Should any of these institutions fail to perform their obligations when contractually required, our financial condition could be adversely affected.

Rising interest rates can increase costs.costs and impact the value of the Company’s assets.

The Company is exposed to market risk from financial instruments primarily from changes in market interest rates. Such risks derive from the refinancing of debt at or prior to maturity, from exposure to interest rate fluctuations inon floating rate debt and from derivative instruments utilized to swap fixed rate debt to floating rates or to hedge rates in anticipation of future debt issuances. Increases inRising interest rates wouldincreased and may continue to increase our interest expense and the costs of refinancing existing debt. Higher interest rates also increased and could continue to increase capitalization rates, which may lead to reduced valuations of the Company’s assets.

Failure to hedge effectively against interest rate changes may adversely affect our results of operations.

From time to time when we anticipate issuing debt securities, we may seek to limit our exposure to fluctuations in interest rates during the period prior to the pricing of the securities by entering into interest rate hedging contracts. Also, from time to time we may rely on interest rate hedging contracts to limit our exposure under variable rate debt to unfavorable changes in market interest rates. The settlement of interest rate hedging contracts may involve material charges. In addition, our use of interest rate hedging arrangements may expose us to additional risks, including a risk that a counterparty to a hedging arrangement may default on the contract. There can be no assurance that our hedging activities will be effective and have the desired beneficial impact on our results of operations or financial condition.

Insufficient cash flow could affect our ability to service existing debt and create refinancing risk.

We are subject to risks normally associated with debt financing, including the risk that our cash flow will be insufficient to meet required payments. We may not be able to refinance existing debt and if we can, the terms of such refinancing may be less favorable than the terms of existing indebtedness. Our inability to refinance, extend or repay debt with proceeds from other capital market transactions would negatively impact our financial condition. If the debt is secured, the mortgage holder may also foreclose on the property.

15

Table of Contents

A significant downgrade in our credit ratings could adversely affect our performance.

A significant downgrade in our credit ratings, while not affecting our ability to draw proceeds under the Company’s revolving credit facility, would cause the corresponding borrowing costs to increase, impact our ability to borrow secured and unsecured debt, and potentially impair our ability to access the commercial paper market or otherwise limit our access to capital. In addition, a downgrade below investment grade would likely cause us to lose access to the commercial paper markets and would require us to post cash collateral and/or letters of credit in favor of some of our secured lenders to cover our self-insured property and liability insurance deductibles or to obtain lower deductible insurance compliant with the lenders’ requirements at the lower ratings level.

Financial covenants could limit operational flexibility and affect our overall financial position.

The terms of our credit agreements, including our revolving credit facility and the indentures under which a substantial portion of our unsecured debt was issued, require us to comply with a number of financial covenants. These covenants may limit our flexibility to run our business and breaches of these covenants could result in defaults under the instruments governing the applicable indebtedness and trigger a cross default of other debt.

Some of our properties are financed with tax-exempt bonds or otherwise contain restrictive covenants or deed restrictions, including affordability requirements, which limit income from certain properties. The Company monitors compliance with the restrictive covenants and deed restrictions that affect these properties. While we generally believe that the interest rate benefit from financing properties with tax-exempt bonds more than outweighs any loss of income due to restrictive covenants or deed restrictions, this may not always be the case. Some of these requirements are complex, and our failure to comply with them may subject us to material fines or liabilities.

We may change the dividend policy for our securities in the future.

The decision to declare and pay dividends on our securities, as well as the timing, amount and composition of any such future dividends, is at the discretion of the Board of Trustees and will depend on actual and projected financial conditions, the Company’s actual and projected liquidity and operating results, the Company’s projected cash needs for capital expenditures and other investment activities and such other factors as the Company’s Board of Trustees deems relevant.relevant. The Board of Trustees may modify our dividend policy from time to time and any change in our dividend policy could negatively impact the market price of our securities.

Issuances or sales of our Common Shares or Units may be dilutive.

Any potential additional issuance of Common Shares (including those issued under our At-The-Market ("ATM") program) or OP Units would reduce the percentage of our Common Shares and OP Units owned by existing investors. In most circumstances, shareholders and unitholders will not be entitled to vote on whether or not we issue additional Common Shares or Units. In addition, depending on the terms and pricing of additional offerings of our Common Shares or Units along with the value of our properties, our shareholders and unitholders could experience dilution in both the book value and fair value of their Common Shares or Units, as well as dilution in our actual and expected earnings per share, funds from operations (“FFO”) per share and Normalized FFO per share.

Regulatory and Tax Risks

The adoption of, or changes in, rent control or rent stabilization regulations and eviction regulations in our marketsrestrictions could have an adverse effect on our operations and property values.

AIn part due to increasing pressure from advocacy groups, a growing number of state and local governments have enacted and may continue to consider enacting and/or expanding rent control, or rent stabilization, eviction moratoriums or other similar regulations. In addition, the federal government has recently considered imposing rent regulations which have limited andon multifamily properties secured by government-sponsored debt. These regulations specifically and/or effectively limit or could continue to limit in broadening ways our ability to raise rents or charge certain fees either(either of which could have a retroactive effect. We continue to see increases in governments considering or being urged by advocacy groups to consider rent forgiveness, rent control or rent stabilization regulations or expand coverage of existing regulations in our markets.  These regulations may also make changes to and/or expand eviction and other tenants’ rights regulations that may limit our ability toeffect), enforce residents’ or tenants’ contractual rentalrent obligations (such as eviction moratoriums), or pursue collections, or charge certain fees,all of which could have an adverse impact on our operations and property values.

Compliance or failure to comply with regulatory requirements could result in substantial costs.

Our properties are subject to various federal, state and local regulatory requirements, such as state and local fire and life safety requirements, building and zoning codes, environmental and other related regulations, and federal, state and local accessibility requirements, including and in addition to those imposed by the Americans with Disabilities Act and the Fair Housing Act. Noncompliance could result in fines, subject us to lawsuits and require us to remediate or repair the noncompliance. Existing requirements could change and compliance with future requirements may require significant unanticipated expenditures that could adversely affect our financial condition or results of operations.

16

Table of Contents

Environmental problems are possible and can be costly.

Federal, state and local laws and regulations relating to the protection of the environment may require current or previous owners or operators of real estate to investigate and clean up hazardous or toxic substances at such properties. The owner or operator may have to pay a governmental entity or third parties for property damage and for investigation and clean-up costs incurred by such parties in connection with the contamination. These laws typically impose clean-up responsibility and liability without regard to whether the owner or operator knew of or caused the presence of the contaminants. Even if more than one person may have been responsible for the contamination, each person covered by the environmental laws may be held responsible for all of the clean-up costs incurred. Third parties may also sue the owner or operator of a site for damages and costs resulting from environmental contamination emanating from

that site. We cannot be assured that existing environmental assessments of our properties reveal all environmental liabilities, that any prior owner of any of our properties did not create a material environmental condition not known to us, or that a material environmental condition does not otherwise exist as to any of our properties.

Changes in U.S. accounting standards may materially and adversely affect the reporting of our operations.

The Company follows GAAP, which is established by the Financial Accounting Standards Board (“FASB”), an independent body whose standards are recognized by the Securities and Exchange Commission (“SEC”) as authoritative for publicly held companies. The FASB and the SEC create and interpret accounting standards and may issue new accounting pronouncements or change the interpretation and application of these standards that govern the preparation of our financial statements.statements. These changes could have a material impact on our reported consolidated results of operations and financial position.

Any weaknesses identified in our internal control over financial reporting could result in a decrease of our share price.

Section 404 of the Sarbanes-Oxley Act of 2002 requires us to evaluate and report on our internal control over financial reporting. If we identify one or more material weaknesses in our internal control over financial reporting, we could lose investor confidence in the accuracy and completeness of our financial reports, which in turn could have a negative impact on our share price.

Our failure to qualify as a REIT would have serious adverse consequences to our security holders.

We plan to continue to meet the requirements for taxation as a REIT. Many of these requirements, for which there is limited judicial and administrative interpretation, however, are highly technical and complex. Therefore, we cannot guarantee that we have qualified or will qualify as a REIT in the future. The determination that we are a REIT requires an analysis of various factual matters that may not be totally within our control. To qualify as a REIT, our assets must be substantially comprised of real estate assets as defined in the Internal Revenue Code of 1986, as amended (the “Code”), and related guidance and our gross income must generally come from rental and other real estate or passive related sources that are itemized in the REIT tax laws. We are also required to distribute to security holders at least 90% of our REIT taxable income excluding net capital gains.

If we fail to qualify as a REIT, we would be subject to U.S. federal income tax at regular corporate rates (including, for years prior to 2018, any alternative minimum tax) and would have to pay significant income taxes unless the Internal Revenue Service (“IRS”) granted us relief under certain statutory provisions. In addition, we would remain disqualified from taxation as a REIT for four years following the year in which we failed to qualify as a REIT. We would therefore have less money available for investments or for distributions to security holders and would no longer be required to make distributions to security holders. This would likely have a significant negative impact on the value of our securities.

In addition, certain of our subsidiary entities have elected to be taxed as REITs. As such, each must separately satisfy all of the requirements to qualify for REIT status. If a subsidiary REIT did not satisfy such requirements, and certain relief provisions did not apply, it would be taxed as a regular corporation and its income would be subject to U.S. federal income taxation. Failure to comply with these complex REIT rules at the subsidiary REIT level can have a material and detrimental impact to EQR’s REIT status.

Gain on disposition of assets held for sale in the ordinary course of business is subject to 100% tax.

Any gain resulting from transfers of properties we hold as inventory or primarily for sale to customers in the ordinary course of business is treated as income from a prohibited transaction subject to a 100% penalty tax unless certain safe harbor exceptions set forth in the Code apply. We do not believe that our transfers or disposals of property are prohibited transactions. However, whether property is held for investment purposes is a question that depends on all the facts and circumstances surrounding the particular transaction. The IRS may contend that certain transfers or dispositions of properties by us or contributions of properties are prohibited transactions. While we believe the IRS would not prevail in any such dispute, if the IRS were to argue successfully that a transfer or disposition of property constituted a prohibited transaction, we would be required to pay a 100% penalty tax on any gain allocable to us from the prohibited transaction. In addition, income from a prohibited transaction might adversely affect our ability to satisfy the income tests for qualification as a REIT.

We may be subject to legislative or regulatory tax changes that could negatively impact our financial condition.

At any time, U.S. federal income tax laws governing REITs or impacting real estate or the administrative interpretations of those laws may be enacted or amended. We cannot predict if or when any new U.S. federal income tax law, regulation or administrative interpretation, or any amendment to any existing U.S. federal income tax law, IRS and U.S. Department of Treasury regulations or other administrative guidance, will be adopted or become effective and any such law, regulation or interpretation may take effect retroactively. The Company and our shareholders could be negatively impacted by any such change in, or any new, U.S. federal income tax law, regulations or administrative guidance.

Distribution requirements may limit our flexibility to manage our portfolio.

In order to maintain qualification as a REIT under the Code, a REIT must annually distribute to its shareholders at least 90% of its REIT taxable income, excluding the dividends paid deduction and net capital gains. To the extent the REIT does not distribute all of its net capital gain, or distributes at least 90%, but less than 100% of its REIT taxable income, it will be required to pay regular U.S. federal income tax on the undistributed amount at corporate rates. In addition, we will be subject to a 4% nondeductible excise tax on amounts, if any, by which distributions we pay in any calendar year are less than the sum of 85% of our ordinary income, 95% of our net capital gains and 100% of our undistributed income from prior years. We may not have sufficient cash or other liquid assets to meet the 90% distribution requirement. We may be required from time to time, under certain circumstances, to accrue as income for tax purposes interest and rent earned but not yet received. We may incur a reduction in tax depreciation without a reduction in capital expenditures. Difficulties in meeting the 90% distribution requirement might arise due to competing demands for our funds or due to timing differences between tax reporting and cash distributions, because deductions may be disallowed, income may be reported before cash is received, expenses may have to be paid before a deduction is allowed or because the IRS may make a determination that adjusts reported income. In addition, gain from the sale of property may exceed the amount of cash received on a leverage-neutral basis. A substantial increase to our taxable income may reduce the flexibility of the Company to manage its portfolio through dispositions of properties other than through tax deferred transactions, such as Section 1031 exchanges, or cause the Company to borrow funds or liquidate investments on unfavorable terms in order to meet these distribution requirements. If we do not dispose of our properties through tax deferred transactions, we may be required to distribute the gain proceeds to shareholders or pay income tax. If we fail to satisfy the 90% distribution requirement and are unable to cure the deficiency, we would cease to be taxed as a REIT, resulting in substantial tax-related liabilities.

We have a share ownership limit for REIT tax purposes.

To remain qualified as a REIT for U.S. federal income tax purposes, not more than 50% in value of our outstanding Shares may be owned, directly or indirectly, by five or fewer individuals at any time during the last half of any year. To facilitate maintenance of our REIT qualification, our Declaration of Trust, subject to certain exceptions, prohibits ownership by any single shareholder of more than five percent of the lesser of the number or value of any outstanding class of common or preferred shares (the “Ownership Limit”). Absent an exemption or waiver granted by our Board of Trustees, securities acquired or held in violation of the Ownership Limit will be transferred to a trust for the exclusive benefit of a designated charitable beneficiary, and the security holder’s rights to distributions and to vote would terminate. A transfer of Shares may automatically be deemed void if it causes a person to violate the Ownership Limit. The Ownership Limit could delay or prevent a change in control and, therefore, could affect our security holders’ ability to realize a premium over the then-prevailing market price for their Shares. To reduce the ability of the Board to use the Ownership Limit as an anti-takeover device, the Company’s Ownership Limit requires, rather than permits, the Board to grant a waiver of the Ownership Limit if the individual seeking a waiver demonstrates that such ownership would not jeopardize the Company’s status as a REIT.

Tax elections regarding distributions may impact future liquidity of the Company or our shareholders.

Under certain circumstances we have made and/or may consider making in the future, a tax election to treat certain distributions to shareholders made after the close of a taxable year as having been distributed during such closed taxable year. This election, which is provided for in the Code, may allow us to avoid increasing our dividends or paying additional income taxes in the current year. However, this could result in a constraint on our ability to decrease our dividends in future years without creating risk of either violating the REIT distribution requirements or generating additional income tax liability. In addition, the Company may be required to pay interest to the IRS based on such a distribution.

In order to retain liquidity and continue to satisfy the REIT distribution requirements, the Company could issue shares rather than pay a dividend entirely in cash to shareholders. The IRS has published several rulings which have allowed REITs to offer shareholders the choice between shares or cash as a form of payment of a dividend (an “elective stock dividend”). However, REITs are generally required to structure the cash component to be no less than 20% of the total dividend paid. Therefore, it is possible that the total tax burden to shareholders resulting from an elective stock dividend may exceed the amount of cash received by the shareholder.

Inapplicability of Maryland law limiting certain changes in control.

Certain provisions of Maryland law applicable to REITs prohibit “business combinations” (including certain issuances of equity securities) with any person who beneficially owns ten percent or more of the voting power of outstanding securities, or with an affiliate

who, at any time within the two-year period prior to the date in question, was the beneficial owner of ten percent or more of the voting power of the Company’s outstanding voting securities (an “Interested Shareholder”), or with an affiliate of an Interested

18

Table of Contents

Shareholder. These prohibitions last for five years after the most recent date on which the Interested Shareholder became an Interested Shareholder. After the five-year period, a business combination with an Interested Shareholder must be approved by two super-majority shareholder votes unless, among other conditions, holders of common shares receive a minimum price for their shares and the consideration is received in cash or in the same form as previously paid by the Interested Shareholder for its common shares. As permitted by Maryland law, however, the Board of Trustees of the Company has opted out of these restrictions with respect to any business combination involving Sam Zell and certain of hisSamuel Zell's affiliates and persons acting in concert with them. Consequently, the five-year prohibition and the super-majority vote requirements will not apply to a business combination involving us and/or any of them. Such business combinations may not be in the best interest of our security holders.

General Risk Factors

Risk of Pandemics or Other Health Crisis.Crises.

A pandemic, epidemicPandemics, epidemics or other health crisis, similar tocrises have and could in the recent outbreak of COVID-19, affectingfuture disrupt our business. Both global and locally targeted health events could materially affect areas where our properties, corporate/regional offices or major service providers are locatedlocated. These events have and could in the future have an adverse effect on our business, results of operations, financial condition and liquidity in a number of ways, including, but not limited to:

To the extent a pandemic, epidemic or other health crisis adversely affects our business, results of operations, cash flows and financial condition.condition, it may also continue to heighten many of the other risks described elsewhere in this Item 1A, Risk Factors.

Significant inflation could negatively impact our business.

Substantial inflationary pressures can adversely affect us by disproportionately increasing the costs of land, materials, labor and other costs needed to operate our business. In a highly inflationary environment, we may not be able to raise rental rates at or above the rate of inflation, which could reduce our profit margins. If we are unable to increase our rental prices to offset the effects of inflation, our business, results of operations, cash flows and financial condition could be adversely affected. In addition, interest rate increases enacted to combat inflation have caused market disruption and could continue to prevent us from acquiring or disposing of assets on favorable terms or at all.

The occurrence of cyber incidents, or a deficiency in our cybersecurity, could negatively impact our business by causing a disruption to our operations, a compromise or corruption of our confidential information, and/or damage to our reputation and business relationships, all of which could negatively impact our financial results.

A cybercybersecurity incident is an intentional attackunauthorized occurrence, or an unintentional eventa series of related unauthorized occurrences, on or conducted through the Company's information systems that jeopardizes the confidentiality, integrity, or availability of our information systems or any information residing therein. These events can include gaining unauthorized access to systems to disrupt payment collections and operations, corrupt data or steal confidential information, including information regarding our residents, prospective residents, employees and employees’ dependents.

Despite system redundancy, the implementation of security measures, required employee awareness training and the existence of a disaster recovery plan for our internal information technology systems, our systems and systems maintained by third-party vendors with which we do business are vulnerable to damage from any number of sources. We face risks associated with security breaches, whether through cyber attacks or cyber intrusions over the Internet, malware, computer viruses, attachments to emails, phishing attempts, social engineering, ransomware or other scams, persons inside our organization or persons/vendors with access to our systems and other significant disruptions of our information technology networks and related systems, including property infrastructure. These risks have increased due to increased reliance on remote working and other electronic interactions with our current and prospective residents. Our information technology networks and related systems are essential to the operation of our business and our ability to perform day-to-day operations. We use these systems to manage our resident and vendor relationships, internal communications, accounting and record-keeping systems and many other key aspects of our business. Our operations rely on the secure processing, storage and transmission of confidential and other information in our computer systems and networks, which also depend on the strength of our procedures and the effectiveness of our internal controls as well as those of vendors with whom we do business. Even the most well-protected information, networks, systems and facilities remain potentially vulnerable because the techniques used in such attempted security breaches evolve and generally are not recognized until launched against a target, and in some cases are designed not to be detected and, in fact, may not be detected. Accordingly, we may be unable to anticipate these techniques or to implement adequate security barriers or other preventative measures, and thus it is impossible for us to entirely mitigate this risk.

We may periodically collect and holdstore personally identifiable information of our residents and prospective residents in connection with our leasing activities, and we may collect and holdstore personally identifiable information of our employees and their dependents. In addition, we often engage third-party service providers that may have access to such personally identifiable information in connection with providing necessary information technology, security and other business services to us. TheDespite the fact that we monitor and perform a comprehensive review of businesses that we contract with that represent a cybersecurity risk to the organization, the systems of ourthese third-party service providers may contain defects in design or other problems that could unexpectedly compromise personally identifiable information. Although we make efforts to maintain the security and integrity of our information technology networks and those of our third-party providers and we have implemented various measures to manage the risk of a security breach or disruption, there can be no assurance that our security efforts and measures will be effective or that attempted security breaches or disruptions would not be successful or damaging.

We address potential breaches or disclosure of this confidential personally identifiable information by implementing a variety of security measures intended to protect the confidentiality and security of this information including (among others):  (a) engaging reputable, recognized firms to help us design and maintain our information technology and data security systems; (b) conducting periodic testing and verification of information and data security systems, including performing ethical hacks of our systems to discover where any vulnerabilities may exist; and (c) providing periodic employee awareness training around phishing and other scams, malware and other cyber risks.  The Company also has a cyber liability insurance policy to provide some coverage for certain risks arising out of data and network breaches and data privacy regulations which provides a policy aggregate limit and a per occurrence deductible.  Cyber liability insurance generally covers, among other things, costs associated with the wrongful release, through inadvertent breach or network attack, of personally identifiable information.  However, there can be no assurance that these measures will prevent a cyber incident or that our cyber liability insurance coverage will be sufficient in the event of a cyber incident.

A breach or significant and extended disruption in the function of our systems, including our primary website, could damage our reputation and cause us to lose residents and revenues, result in a violation of applicable privacy and other laws, generate third-party

19

Table of Contents

claims, result in the unintended and/or unauthorized public disclosure or the misappropriation of proprietary, personally identifiable and confidential information and require us to incur significant expenses to address and remediate or otherwise resolve these kinds of issues. We may not be able to recover these expenses in whole or in any part from our service providers, our insurers or any other responsible parties. As a result, there can be no assurance that our financial results would not be negatively impacted.

We are also subject to laws, rules, and regulations in the United States, such as the California Consumer Privacy Rights Act (“CCPA”CPRA”), relating to the collection, use, and security of resident, customer, employee and other data. Evolving compliance and operational requirements under the CCPACPRA and the privacy laws of other jurisdictions in which we operate may impose significant costs that are likely to increase over time. Our failure to comply with laws, rules and regulations related to privacy and data protection could harm our business or reputation or subject us to fines and penalties.

The Audit Committee is primarily responsible for oversight of the risk management process related to cybersecurity and typically meets no less often than annually with Company information technology personnel to discuss recent trends in cyber risks and the Company’s strategy to defend its business systems and information against cyber attacks as well as the Company’s efforts to comply with data privacy laws such as the CCPA.

Our business and operations rely on specialized information technology systems, the failure of or inadequacy of which could impact our business.

Our ability to identify, implement and maintain appropriate information technology systems differentiates and creates competitive advantages for us in the operations of our business. These systems often are developed and hosted by third partythird-party vendors whom we rely upon for ongoing maintenance, upgrades and enhancements. While we maintain a rigorous process around selecting appropriate information technology systems and partnering with vendors, our failure to adequately do so could negatively impact our operations and competitive position.

Our approach to artificial intelligence may not be successful and could adversely affect our business.

We have incorporated and may continue to incorporate the use of generative artificial intelligence ("AI") within our business, and these solutions and features may become more important to our operations or to our future growth over time. Our research and development of AI remains ongoing. There can be no assurance that we will realize the desired or anticipated benefits, or any benefits, and we may fail to properly implement such technology. AI presents risks, challenges and unintended consequences that could affect our adoption and use of this technology. Our competitors or other third parties may incorporate AI in their business operations more quickly or more successfully than we do, which could impair our ability to compete effectively and adversely affect our results of

operations. Additionally, the complex and rapidly evolving landscape around AI may expose us to claims, demands and proceedings by private parties and regulatory authorities and subject us to legal liability as well as reputational harm.

We depend on our key personnel.

We depend on the efforts of our trustees and executive officers. If one or more of them resign or otherwise cease to be employed by us, our business and results of operations and financial condition could be adversely affected.

Litigation risk could affect our business.

We are involved and may becomecontinue to be involved in legal proceedings, claims, class actions, inquiries and governmental investigations in the ordinary course of business. These legal proceedings may include, but are not limited to, proceedings related to consumer, shareholder, securities, antitrust, employment, environmental, development, condominium conversion, tort, eviction and commercial legal issues. Litigation can be lengthy and expensive, and it can divert management's attention and resources. Results cannot be predicted with certainty, and an unfavorable outcome in litigation could result in liability material to our financial condition or results of operations.

Insurance policies can be costly and may not cover all losses, which may adversely affect our financial condition or results of operations.

The Company’s property, general liability and workers compensation insurance policies provide coverage with substantial per occurrence deductibles and/or self-insured retentions. These self-insurance retentions can be a material portion of insurance losses in excess of the base deductibles. While the Company has previously purchased incremental insurance coverage in the event of multiple non-catastrophic occurrences within the same policy year, these substantial deductible and self-insured retention amounts do expose the Company to greater potential for uninsured losses and this additional multiple occurrences coverage may not be available at all or on commercially reasonable terms in the future. We believe the policy specifications and insured limits of these policies are adequate and appropriate; however, there are certain types of extraordinary losses whichwe may not always be adequately covered under ourable to place the desired amount of third-party coverage due to a significant increase in insurance program.premiums and deductibles or a decrease in the availability of coverage, a combination of which have exposed and could further expose the Company to uninsured losses. As a result, our financial results could be adversely affected and may vary significantly from period to period.

The Company relies on third-party insurance providers for its property, general liability, workers compensation and other insurance, and should any of them experience liquidity issues or other financial distress, it could negatively impact their ability to pay claims under the Company’s policies.

Earthquake risk: Our policies insuring against earthquake losses have substantial deductibles which are applied to the values of the buildings involved in the loss. With the geographic concentration of our properties, a single earthquake affecting a market may have a significant negative effect on our financial condition and results of operations. We cannot assure that an earthquake would not cause damage or losses greater than insured levels. In the event of a loss in excess of insured limits, we could lose our capital invested in the affected property or market, as well as anticipated future revenue.

20

Table of Contents

Terrorism risk: The Company has terrorism insurance coverage which excludes losses from nuclear, biological and chemical attacks. In the event of a terrorist attack impacting one or more of our properties, we could lose the revenues from the property, our capital investment in the property and possibly face liability claims from residents or others suffering injuries or losses.

Catastrophic weather and natural disaster risk: Our properties may be located in areas that could experience catastrophic weather and other natural disasters from time to time, including wildfires, snow or ice storms, hail, windstorms or hurricanes, drought, flooding or other severe disasters. These severe weather and natural disasters could cause substantial damages or losses to our properties which may not be covered or could exceed our insurance coverage. Exposure to this risk could also result in a decrease in demand for properties located in these areas or affected by these conditions.

Climate change risk: To the extent that significant changes in the climate occur in areas where our properties are located, we may experience severe weather, which may result in physical damage to or decrease the demand for properties located in these areas or affected by these conditions. Should the impact of climate change be material in nature, significant property damage or destruction of our properties could result. In addition, climate change could cause a significant increase in insurance premiums and deductibles or a decrease in the availability of coverage, either of which could expose the Company to even greater uninsured losses. Our financial condition or results of operations may be adversely affected. In addition, changes in federal, state and local legislation and regulation based on concerns about climate change could adversely impact the value of our properties or result in increased capital expenditures or operating expenses on our existing properties and our new development properties.

Provisions of our Declaration of Trust and Bylaws could inhibit changes in control.

Certain provisions of our Declaration of Trust and Bylaws may delay or prevent a change in control of the Company or other transactions that could provide the security holders with a premium over the then-prevailing market price of their securities or which might otherwise be in the best interest of our security holders. This includes the Ownership Limit described above. While our existing preferred shares/preference units do not have all of these provisions, any future series of preferred shares/preference units may have certain voting provisions that could delay or prevent a change in control or other transactions that might otherwise be in the interest of our security holders. Our Bylaws require certain information to be provided by any security holder, or persons acting in concert with such security holder, who proposes business or a nominee at an annual meeting of shareholders, including disclosure of information related to hedging activities and investment strategies with respect to our securities. These requirements could delay or prevent a change in control or other transactions that might otherwise be in the interest of our security holders. The Board of Trustees may use its powers to issue preferred shares and to set the terms of such securities to delay or prevent a change in control of the Company even if a change in control were in the interest of the security holders.

Item 1B. Unresolved Staff Comments

None.

Item 1C. Cybersecurity

Risk management and strategy

We have an enterprise-wide information security program designed to protect our information systems from cybersecurity threats. We identify and assess risks from cybersecurity threats by monitoring and evaluating our digital assets and our risk profile using various methods. We monitor security events that are internally discovered or externally reported that may affect our systems and have processes and procedures to assess those events for potential cybersecurity impact or risk and consequently improve our security measures and planning. Additionally, we work with third parties from time to time that assist us in refining our cybersecurity risk strategy in order to identify, assess and manage cybersecurity risks, including professional services firms and consulting firms. We seek to detect and investigate unauthorized attempts and attacks against our network and services, and to minimize their occurrence and recurrence through changes or updates to our internal processes and tools and changes or updates to our services; however, we remain potentially vulnerable to known or unknown threats.

Our cybersecurity incident response processes are designed to escalate certain cybersecurity events to members of management depending on the circumstances. Key members of management, including representatives from IT, operations, legal, finance, risk management and internal audit, serve on the Company’s senior security incident response team to help the Company mitigate and remediate cybersecurity incidents of which they are notified, and certain cybersecurity incidents are escalated to the Company’s executives. In addition, the Company’s incident response processes include potential reporting to the Audit Committee of our Board of Trustees for certain cybersecurity incidents.

We also have a third-party risk management program in place to manage cybersecurity risks associated with third-party service providers. While we do maintain processes and procedures to identify, prioritize and assess risks associated with third-party service providers, we must rely on third parties to augment our security program, and we cannot ensure in all circumstances that their efforts will be successful.

While to date we have not experienced a cybersecurity threat or incident that resulted in a material adverse impact to our business or operations, there can be no guarantee that we will not experience such an incident in the future. Any significant disruption to our systems could adversely affect our business and results of operations. Further, a cyber incident impacting our systems or a third-party’s systems could subject us to business, regulatory, litigation and reputational risk, which could have a negative effect on our business, financial condition and results of operations.

Notwithstanding the extensive approach we take to cybersecurity, we may not be successful in preventing or mitigating a cybersecurity incident that could have a material adverse effect on us. While we maintain cybersecurity insurance, the costs related to cybersecurity threats or disruptions may not be fully insured. See Item 1A, Risk Factors, for a discussion of cybersecurity risks.

Governance

Our Information Technology Security Team, under the oversight of our Senior Vice President of IT and the leadership of our VP of IT Infrastructure and Security, is responsible for our overall information security strategy, policy, security engineering, operations and cyber threat detection and response. The Information Technology Security Team manages and continually enhances a robust enterprise security structure with the ultimate goal of minimizing cybersecurity incidents to the extent feasible, while simultaneously increasing our system resilience in an effort to minimize the business impact should an incident occur. Our Information Technology Security Team possesses decades of experience in navigating cybersecurity threats and mitigating associated risks as a result of holding similar positions at other large companies. Most members of the team hold degrees in cybersecurity and/or related disciplines, have cybersecurity certifications such as Certified Information Systems Security Professional (CISSP) and/or periodically attend various cyber-focused conferences and training programs. Specifically, our Senior Vice President of IT and our VP of IT Infrastructure and Security combined have over 30 years of technology and cybersecurity experience. The team provides regular reports to senior management and affected departments on various cybersecurity threats, assessments and findings.

The Audit Committee of our Board of Trustees oversees our annual enterprise risk management assessment, where we assess key risks within the Company, including security and technology risks and cybersecurity threats. The Audit Committee oversees our ongoing cybersecurity risk management efforts and regularly receives detailed reports from representatives of our Information Technology Security Team addressing a wide range of related topics. At least annually, our IT leadership (and external cybersecurity experts if applicable) reviews key cybersecurity strategies and policies with the full Board of Trustees, including risk assessments, mitigation strategies, areas of emerging risks, incidents and industry trends and other areas of importance.

Item 2. Properties

As of December 31, 2020,2023, the Company, directly or indirectly through investments in title holding entities, owned all or a portion of 304302 properties located in 910 states and the District of Columbia consisting of 77,88980,191 apartment units. See Item 1, Business, for additional information regarding the Company’s properties and the markets/metro areas upon which we are focused. The Company’s properties are summarized by building type in the following table:

The Company’s properties are summarized by ownership type in the following table:

21

Table of Contents

The following table sets forth certain information by market relating to the Company’s properties at December 31, 2020:

Note: Projects under development are not included in the Portfolio Summary until construction has been completed.

As of December 31, 2020, the Company’s same store occupancy was 94.4% and its total portfolio-wide occupancy, which includes completed development properties in various stages of lease-up, was 94.2%.  Certain of the Company’s properties are encumbered by mortgages and additional detail can be found on Schedule III – Real Estate and Accumulated Depreciation.  Garden-style areGarden is generally defined as properties with two and/or three story buildings while mid-rise/mid/high-rise areis generally defined as properties with greater than three story buildings. These two property types typically provide residents with amenities, such as rooftop decks and swimming pools, fitness centers and community rooms. In addition, many of our urban properties have non-residential components, such as parking garages and/or retail spaces.

The Company’s properties are summarized by ownership type in the following table:

22

The following table sets forth certain information by market relating to the Company’s properties at December 31, 2023:

Note: Projects under development are not included in the Portfolio Summary until construction has been completed.

The following tables provide a rollforward of the apartment units included in Same Store Properties (please refer to the Definitions section in Item 7, Management’s Discussion and Analysis of Financial Condition and Results of Operations) and a reconciliation of apartment units included in Same Store Properties to those included in Total Properties for the year ended December 31, 2023:

Note: Properties are considered “stabilized” when they have achieved 90% occupancy for three consecutive months. Properties are included in same store when they are stabilized for all of the current and comparable periods presented.

For the year ended December 31, 2023, the Company’s same store Physical Occupancy was 95.9% and its total portfolio-wide Physical Occupancy, which includes completed development properties in various stages of lease-up, was 95.4%. Certain of the Company’s properties are encumbered by mortgages and additional detail can be found on Schedule III – Real Estate and Accumulated Depreciation.

The properties currently in various stages of development and lease-up at December 31, 2020, all of which are consolidated,2023 are included in the following table: