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

None

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.

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

The abbreviations and terms set forth below are used throughout this report and have the meanings assigned to them below:

In this report, we make statements concerning our expectations, beliefs, plans, objectives, goals, strategies, and future events or performance. These statements are "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Exchange Act. Readers are cautioned not to place undue reliance on these forward-looking statements. Forward-looking statements may be identified by reference to a future period or periods or by the use of terms such as "anticipates," "believes," "could," "estimates," "expects," "forecasts," "goals," "guidance," "intends," "may," "objectives," "plans," "possible," "potential," "projects," "seeks," "should," "targets," "will," or variations of these terms.

Forward-looking statements include, among other things, statements concerning management's expectations and projections regarding earnings, completion of capital projects, sales and customer growth, rate actions and related filings with regulatory authorities, environmental and other regulations, andincluding associated compliance costs, legal proceedings, effective tax rates, pension and OPEB plans, fuel costs, sources of electric energy supply, coal and natural gas deliveries, remediation costs, environmentalclimate-related matters, the ESG Progress Plan, liquidity and capital resources, and other matters.

Forward-looking statements are subject to a number of risks and uncertainties that could cause our actual results to differ materially from those expressed or implied in the statements. These risks and uncertainties include those described in risk factors as set forth in this report and our 20192020 Annual Report on Form 10-K, and those identified below:

Wisconsin Public Service Corporation serves approximately 451,600454,600 electric customers and 334,000336,600 natural gas customers.

As used in these notes, the term "financial statements" refers to the condensed financial statements. This includes the income statements, balance sheets, statements of cash flows, and statements of equity, unless otherwise noted. In this report, when we refer to "the Company," "us," "we," "our," or "ours," we are referring to Wisconsin Public Service Corporation.

We have prepared the unaudited interim financial statements presented in this Form 10-Q pursuant to the rules and regulations of the SEC and GAAP. Accordingly, these financial statements do not include all of the information and footnotes required by GAAP for annual financial statements. These financial statements should be read in conjunction with the financial statements and footnotes in our Annual Report on Form 10-K for the year ended December 31, 2019.2020. Financial results for an interim period may not give a true indication of results for the year. In particular, the results of operations for the three and ninesix months ended SeptemberJune 30, 20202021 are not necessarily indicative of expected results for 20202021 due to seasonal variations and other factors, including any continuing financial impacts from the COVID-19 pandemic.

In management's opinion, we have included all adjustments, normal and recurring in nature, necessary for a fair presentation of our financial results.

For more information about our operating revenues, see Note 1(d), Operating Revenues, in our 20192020 Annual Report on Form 10-K.

The following tables present our operating revenues disaggregated by revenue source for our utility segment. We do not have any revenues associated with our other segment. We disaggregate revenues into categories that depict how the nature, amount, timing, and uncertainty of revenues and cash flows are affected by economic factors. Revenues are further disaggregated by electric and natural gas operations and then by customer class. Each customer class within our electric and natural gas operations have different expectations of service, energy and demand requirements, and can be impacted differently by regulatory activities within their jurisdictions.

The following table disaggregates electric utility operating revenues into customer class:

The following table disaggregates natural gas utility operating revenues into customer class:

Other operating revenues consist primarily of the following:

Our exposure to credit losses is related to our accounts receivable and unbilled revenue balances, which are generated from the sale of electricity and natural gas by our regulated utility operations. Our regulated utility operations are included in our utility segment. NaN accounts receivable and unbilled revenue balances were reported in the other segment at SeptemberJune 30, 2021 and December 31, 2020.

We evaluate the collectability of our accounts receivable and unbilled revenue balances considering a combination of factors. For some of our larger customers and also in circumstances where we become aware of a specific customer's inability to meet its financial obligations to us, we record a specific allowance for credit losses against amounts due in order to reduce the net recognized receivable to the amount we reasonably believe will be collected. For all other customers, we use the accounts receivable aging method to calculate an allowance for credit losses. Using this method, we classify accounts receivable into different aging buckets and calculate a reserve percentage for each aging bucket based upon historical loss rates. The calculated reserve percentages are updated on at least an annual basis, in order to ensure recent macroeconomic, political, and regulatory trends are captured in the calculation, to the extent possible. Risks identified that we do not believe are reflected in the calculated reserve percentages, are assessed on a quarterly basis to determine whether further adjustments are required. The incremental reserve included within our allowance for credit losses at September 30, 2020, specific to the economic risks associated with the COVID-19 pandemic, was not significant. We will continue to monitor the economic impacts of COVID-19 and the resulting effects that these impacts may have on the ability of our customers to pay their energy bills.

We monitor our ongoing credit exposure through active review of counterparty accounts receivable balances against contract terms and due dates. Our activities include timely account reconciliation, dispute resolution and payment confirmation. To the extent possible, we work with customers with past due balances to negotiate payment plans, but will disconnect customers for non-payment as allowed by the PSCW, if necessary, and employ collection agencies and legal counsel to pursue recovery of defaulted receivables. For our larger customers, detailed credit review procedures may be performed in advance of any sales being made. We sometimes require letters of credit, parental guarantees, prepayments or other forms of credit assurance from our larger customers to mitigate credit risk. See Note 17,18, Regulatory Environment, for information on certain regulatory actions that were and/or are being taken for the purpose of ensuring that essential utility services are available to our customers during the COVID-19 pandemic.

We have included a table below that shows our gross third-party receivable balances and related allowance for credit losses.

The decrease in the allowance for credit losses at June 30, 2021, compared to December 31, 2020, was driven by an improvement in past due accounts receivable balances, primarily related to residential customers. Most of the improvement occurred in the second quarter of 2021, which we believe is related to the start of normal collection practices. See Note 18, Regulatory Environment, for the three and nine months ended September 30, 2020, is included below:

The increase in ourthe allowance for credit losses infrom December 31, 2019 to June 30, 2020, was driven by an increase in past due accounts receivable balances from December 31, 2019 to September 30, 2020.balances. This is a trend we generally see over the winter moratorium months, when we are not allowed to disconnect customer service as a result of non-payment. In Wisconsin, the winter moratorium begins on November 1 and ends on April 15. However, as a result of the COVID-19 pandemic and related regulatory orders we have received, we were also unable to disconnect any of our customers during the second and third quartersquarter of 2020. See Note 17, Regulatory Environment, for more information.

The following regulatory assets and liabilities were reflected on our balance sheets at SeptemberJune 30, 20202021 and December 31, 2019.2020. For more information on our regulatory assets and liabilities, see Note 5,6, Regulatory Assets and Liabilities, in our 20192020 Annual Report on Form 10-K.