阿曼瑞恩 2025年度报告

2 0 2 5A N N U A L R E P O R T UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549 FORM 10-K ☒Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934for the fiscal year ended December 31, 2025 Indicate by check mark if each registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Ameren CorporationYes☒No☐Union Electric CompanyYes☒No☐Ameren Illinois CompanyYes☒No☐ Indicate by check mark if each registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Ameren CorporationYes☐No☒Union Electric CompanyYes☐No☒Ameren Illinois CompanyYes☐No☒ Indicate by check mark whether each registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the SecuritiesExchange 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. Ameren CorporationYes☒No☐Union Electric CompanyYes☒No☐Ameren Illinois CompanyYes☒No☐ Indicate by check mark whether each registrant has submitted electronically every Interactive Data File required to be submittedpursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that theregistrant was required to submit such files). Ameren CorporationYes☒No☐Union Electric CompanyYes☒No☐Ameren Illinois CompanyYes☒No☐ Indicate by check mark whether each registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smallerreporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reportingcompany,” and “emerging growth company” in Rule 12b-2 of the Exchange Act. Ameren CorporationLarge accelerated filer☒Accelerated filer☐Non-accelerated filer☐Smaller reporting company☐Emerging growth company☐Union Electric CompanyLarge accelerated filer☐Accelerated filer☐Non-accelerated filer☒Smaller reporting company☐Emerging growth company☐Ameren Illinois CompanyLarge accelerated filer☐Accelerated filer☐Non-accelerated filer☒Smaller reporting company☐Emerging growth company☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period forcomplying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. Ameren CorporationUnion Electric CompanyAmeren Illinois Company Indicate by check mark whether each registrant has filed a report on and attestation to its management’s assessment of theeffectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by theregistered public accounting firm that prepared or issued its audit report. Ameren CorporationUnion Electric CompanyAmeren Illinois Company If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrantincluded in the filing reflect the correction of an error to previously issued financial statements. Ameren CorporationUnion Electric CompanyAmeren Illinois Company Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-basedcompensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). Ameren CorporationUnion Electric CompanyAmeren Illinois Company Indicate by check mark whether each registrant is a shell company (as defined in Rule 12b-2 of the Act). As of June 30, 2025, the aggregate market value of Ameren Corporation’s common stock, $0.01 par value, (based upon the closingprice of the common stock on the New York Stock Exchange on June 30, 2025) held by nonaffiliates was $25,948,493,142. All of the sharesof common stock of the other registrants were held by Ameren Corporation as of June 30, 2025. The number of shares outstanding of each registrant’s classes of common stock as of January 30, 2026, were as follows: Registrant Ameren CorporationUnion Electric CompanyAmeren Illinois Company DOCUMENTS INCORPORATED BY REFERENCE Portions of the definitive proxy statement of Ameren Corporation and portions of the definitive information statements of Union ElectricCompany and Ameren Illinois Company for the 2026 annual meetings of shareholders are incorporated by reference into Part III of thisForm 10-K. TABLE OF CONTENTS PageGLOSSARY OF TERMS AND ABBREVIATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .FORWARD-LOOKING STATEMENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .PART IItem 1.Business. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .