AEE / Ameren Corporation - SEC-Einreichungen, Jahresbericht, Proxy Statement

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 14, 2026

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 14, 2026 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14756 A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 14, 2026

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 14, 2026 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14756 A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 14, 2026

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 14, 2026 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14756 A

As filed with the Securities and Exchange Commission on May 15, 2026

TABLE OF CONTENTS As filed with the Securities and Exchange Commission on May 15, 2026 Registration No.

Security Type

Calculation of Filing Fee Tables S-3 AMEREN CORP Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid Fees Previously Paid Carry Forward Securities Carry Forward Securities 1 Equity Common Stock, $.

POWER OF ATTORNEY

Exhibit 24 POWER OF ATTORNEY WHEREAS, AMEREN CORPORATION, a Missouri corporation (herein referred to as the “Company”), intends to file with the Securities and Exchange Commission, under the Securities Act of 1933, as amended, a registration statement or registration statements on an appropriate form and any amendments thereto registering common stock under the Company’s Dividend Reinvestment and Stock Purchase Plan (DRPlus), as authorized by the Company’s Board of Directors on May 15, 2026; and WHEREAS, each of the individuals identified below is a director of the Company.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the Quarterly Period Ended March 31, 2026 OR ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number Exact name of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the Quarterly Period Ended March 31, 2026 OR ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number Exact name of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the Quarterly Period Ended March 31, 2026 OR ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number Exact name of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 5, 2026 AMEREN CORPORATION (E

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 5, 2026 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Numbe

AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts)

Exhibit 99.2 AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts) Three Months Ended March 31, 2026 2025 Operating Revenues: Electric $ 1,661 $ 1,622 Natural gas 515 475 Total operating revenues 2,176 2,097 Operating Expenses: Fuel and purchased power 433 502 Natural gas purchased for resale 171 169 Other operations and maintenance 491 485 De

Ameren Announces First Quarter 2026 Results

NEWS RELEASE 1901 Chouteau Avenue: St. Louis, MO 63103: Ameren.com Contacts: Media Financial Analysts and Institutional Investors Ameren Communications Andrew Kirk 314.554.2182 314.554.3942 [email protected] [email protected] For Immediate Release Ameren Announces First Quarter 2026 Results •First Quarter Diluted Earnings Per Share (EPS) were $1.28 in 2026 vs. $1.07 in 2025 •Reaffirmed 2026

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.   )

TABLE OF CONTENTS UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.   ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule

ARS

POWERING GROWTH 2025 ANNUAL REPORTUNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Defin

AMEREN CORPORATION Company Order

Exhibit 4.3 AMEREN CORPORATION Company Order March 4, 2026 The Bank of New York Mellon Trust Company, N.A., as Trustee 311 S. Wacker Drive Suite 6200B, Mailbox #44 Chicago, Illinois 60606 Re: 5.00% Senior Notes due 2036 Ladies and Gentlemen: Application is hereby made to The Bank of New York Mellon Trust Company, N.A., a national banking association, as successor trustee (the “Trustee”), under the

Ameren Corporation $400,000,000 5.00% Senior Notes due 2036 Underwriting Agreement

Exhibit 1 Ameren Corporation $400,000,000 5.00% Senior Notes due 2036 Underwriting Agreement February 26, 2026 BNY Mellon Capital Markets, LLC 240 Greenwich Street, 3W New York, New York 10286 J.P. Morgan Securities LLC 270 Park Avenue New York, New York 10017 RBC Capital Markets, LLC Brookfield Place 200 Vesey Street, 8th Floor New York, New York 10281 U.S. Bancorp Investments, Inc. 214 North Try

AMEREN CORPORATION 5.00% SENIOR NOTE DUE 2036

Exhibit 4.4 REGISTERED REGISTERED THIS NOTE IS A GLOBAL NOTE REGISTERED IN THE NAME OF THE DEPOSITARY (REFERRED TO HEREIN) OR A NOMINEE THEREOF AND, UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE FOR THE INDIVIDUAL NOTES REPRESENTED HEREBY AS PROVIDED IN THE INDENTURE REFERRED TO BELOW, THIS NOTE MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE O

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 4, 2026 AMEREN CORPORATION

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 4, 2026 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Num

Security Type

Calculation of Filing Fee Tables S-3 AMEREN CORP Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid 1 Debt Ameren Corporation's 5.

$400,000,000 5.00% Senior Notes due 2036

TABLE OF CONTENTS   Filed pursuant to Rule 424(b)(2)  Registration No. 333-274977 PROSPECTUS SUPPLEMENT (To Prospectus dated October 13, 2023) $400,000,000 5.00% Senior Notes due 2036 Ameren Corporation is offering $400,000,000 principal amount of its 5.00% Senior Notes due 2036, referred to in this prospectus supplement as the “senior notes.” The senior notes will mature on May 15, 2036. We will

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 27, 2026

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 27, 2026 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14

SUPPLEMENTAL INDENTURE DATED FEBRUARY 1, 2026 UNION ELECTRIC COMPANY THE BANK OF NEW YORK MELLON, AS TRUSTEE (SUPPLEMENTAL TO THE INDENTURE OF MORTGAGE AND DEED OF TRUST DATED JUNE 15, 1937, AS AMENDED, EXECUTED BY UNION ELECTRIC COMPANY TO THE BANK

Exhibit 4.2 SUPPLEMENTAL INDENTURE DATED FEBRUARY 1, 2026 UNION ELECTRIC COMPANY TO THE BANK OF NEW YORK MELLON, AS TRUSTEE (SUPPLEMENTAL TO THE INDENTURE OF MORTGAGE AND DEED OF TRUST DATED JUNE 15, 1937, AS AMENDED, EXECUTED BY UNION ELECTRIC COMPANY TO THE BANK OF NEW YORK MELLON, AS TRUSTEE) 4.80% First Mortgage Bonds due 2036 5.55% First Mortgage Bonds due 2056 This instrument was prepared by

SUPPLEMENTAL INDENTURE DATED FEBRUARY 1, 2026 UNION ELECTRIC COMPANY THE BANK OF NEW YORK MELLON, AS TRUSTEE (SUPPLEMENTAL TO THE INDENTURE OF MORTGAGE AND DEED OF TRUST DATED JUNE 15, 1937, AS AMENDED, EXECUTED BY UNION ELECTRIC COMPANY TO THE BANK

Exhibit 4.2 SUPPLEMENTAL INDENTURE DATED FEBRUARY 1, 2026 UNION ELECTRIC COMPANY TO THE BANK OF NEW YORK MELLON, AS TRUSTEE (SUPPLEMENTAL TO THE INDENTURE OF MORTGAGE AND DEED OF TRUST DATED JUNE 15, 1937, AS AMENDED, EXECUTED BY UNION ELECTRIC COMPANY TO THE BANK OF NEW YORK MELLON, AS TRUSTEE) 4.80% First Mortgage Bonds due 2036 5.55% First Mortgage Bonds due 2056 This instrument was prepared by

Union Electric Company $900,000,000 $450,000,000 4.80% First Mortgage Bonds due 2036 $450,000,000 5.55% First Mortgage Bonds due 2056 Underwriting Agreement

Exhibit 1 Union Electric Company $900,000,000 $450,000,000 4.80% First Mortgage Bonds due 2036 $450,000,000 5.55% First Mortgage Bonds due 2056 Underwriting Agreement February 23, 2026 Barclays Capital Inc. BofA Securities, Inc. Mizuho Securities USA LLC MUFG Securities Americas Inc. Wells Fargo Securities, LLC As Representatives of the several Underwriters named in Schedule I to the applicable Pr

Union Electric Company $900,000,000 $450,000,000 4.80% First Mortgage Bonds due 2036 $450,000,000 5.55% First Mortgage Bonds due 2056 Underwriting Agreement

Exhibit 1 Union Electric Company $900,000,000 $450,000,000 4.80% First Mortgage Bonds due 2036 $450,000,000 5.55% First Mortgage Bonds due 2056 Underwriting Agreement February 23, 2026 Barclays Capital Inc. BofA Securities, Inc. Mizuho Securities USA LLC MUFG Securities Americas Inc. Wells Fargo Securities, LLC As Representatives of the several Underwriters named in Schedule I to the applicable Pr

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 27, 2026

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 27, 2026 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14

SUBJECT TO COMPLETION, DATED FEBRUARY 26, 2026

TABLE OF CONTENTS The information contained in this preliminary prospectus supplement is not complete and may be changed.

Ameren Corporation Pricing Term Sheet February 26, 2026

Filed Pursuant to Rule 433 Registration No. 333-274977 Ameren Corporation Pricing Term Sheet February 26, 2026 Issue: 5.00% Senior Notes due 2036 (the “Notes”) Principal Amount: $400,000,000 Coupon (Interest Rate): 5.00% per annum Maturity Date: May 15, 2036 Benchmark Treasury: 4.125% due February 15, 2036 Benchmark Treasury Price: 100-26+ Benchmark Treasury Yield: 4.023% Spread to Benchmark Treas

FORMULA FOR DETERMINING 2026 TARGET PSU AND RSU AWARDS FORMULA FOR DETERMINING 2026 TARGET PERFORMANCE SHARE UNIT ("PSU") AND RESTRICTED STOCK UNIT ("RSU") AWARDS TO BE ISSUED TO NAMED EXECUTIVE OFFICERS

Exhibit 10.29 FORMULA FOR DETERMINING 2026 TARGET PSU AND RSU AWARDS FORMULA FOR DETERMINING 2026 TARGET PERFORMANCE SHARE UNIT ("PSU") AND RESTRICTED STOCK UNIT ("RSU") AWARDS TO BE ISSUED TO NAMED EXECUTIVE OFFICERS The target number of PSUs and RSUs to be issued to each Named Executive Officer listed below for 2026 will be determined in accordance with the following formula: 2026 Target Number

POWER OF ATTORNEY

Exhibit 24.1 POWER OF ATTORNEY WHEREAS, AMEREN CORPORATION, a Missouri corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2025; and WHEREAS, each of the individuals identified below is a director of

2025 Special Restricted Stock Unit Award Agreement October 9, 2025

Exhibit 10.44 Participant: Theresa Shaw You have been awarded the following special equity grant of Restricted Stock Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached Special Restricted Stock Unit Award Agreement. Notice of 2025 Special Restricted Stock Unit Award Grant D

POWER OF ATTORNEY

Exhibit 24.3 POWER OF ATTORNEY WHEREAS, AMEREN ILLINOIS COMPANY, an Illinois corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2025; and WHEREAS, the individual identified below is a director of the

BONUS AGREEMENT

Exhibit 10.45 BONUS AGREEMENT This Bonus Agreement (hereinafter “Agreement”) is entered into this 13th day of November 2025, by and between David M. Feinberg (“Employee”) and Ameren Services Company (“Ameren Services”), a Missouri corporation, on behalf of itself and its parents, subsidiaries and affiliates (collectively, “Ameren” or “Company”) (Employee and Ameren or Company collectively, “Partie

Ameren Corporation Severance Plan for Ameren Officers

Exhibit 10.47 Ameren Corporation Severance Plan for Ameren Officers Plan and Summary Plan Description Amended and Restated Effective January 1, 2026 1 Table of Contents 2 Introduction The Ameren Corporation Severance Plan for Ameren Officers (herein referred to as the “Plan”) is sponsored by Ameren Corporation and is offered to Officers of Ameren Corporation and its participating subsidiaries (ref

2025 Restricted Stock Unit Award Agreement

Exhibit 10.46 2025 Restricted Stock Unit Award Agreement Notice of 2025 Restricted Stock Unit Award Participant: David M. Feinberg You have been awarded the following equity grant of Restricted Stock Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached Restricted Stock Unit

2026 Performance Share Unit Award Agreement

Exhibit 10.42 2026 Performance Share Unit Award Agreement PSU Award- Energy Resource Development Notice of 2026 Performance Share Unit Award (Energy Resource Development) Participant: Grant Date: You have been granted the following Performance Share Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, t

POWER OF ATTORNEY

Exhibit 24.2 POWER OF ATTORNEY WHEREAS, UNION ELECTRIC COMPANY, a Missouri corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2025; and WHEREAS, each of the individuals identified below is a director

Ameren Corporation Severance Plan for Ameren Officers

Exhibit 10.47 Ameren Corporation Severance Plan for Ameren Officers Plan and Summary Plan Description Amended and Restated Effective January 1, 2026 1 Table of Contents 2 Introduction The Ameren Corporation Severance Plan for Ameren Officers (herein referred to as the “Plan”) is sponsored by Ameren Corporation and is offered to Officers of Ameren Corporation and its participating subsidiaries (ref

2026 Ameren Short-Term Incentive Plan Plan Summary Effective January 1, 2026

Exhibit 10.20 2026 Ameren Short-Term Incentive Plan Plan Summary Effective January 1, 2026 1 2 Summary The Ameren Short-Term Incentive Plan (“STIP”) is intended to reward eligible Officers for their contributions to Ameren’s success. The STIP rewards Officers for results in the following categories: financial performance, safety, operational performance, customer, and individual performance during

SCHEDULE I CHANGE OF CONTROL SEVERANCE PLAN PARTICIPANTS EFFECTIVE JANUARY 1, 2026

Exhibit 10.25 SCHEDULE I CHANGE OF CONTROL SEVERANCE PLAN PARTICIPANTS EFFECTIVE JANUARY 1, 2026 Benefit Level - 3 Lindgren, Mark C. * Moehn, Michael * Lyons, Martin J. * Singh, Leonard P. Benefit Level - 2 Schukar, Shawn E. * Shaw, Theresa A. * Eligible for excise tax gross-up provisions (for Officers effective before October 1, 2009)

POWER OF ATTORNEY

Exhibit 24.2 POWER OF ATTORNEY WHEREAS, UNION ELECTRIC COMPANY, a Missouri corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2025; and WHEREAS, each of the individuals identified below is a director

2025 Restricted Stock Unit Award Agreement

Exhibit 10.46 2025 Restricted Stock Unit Award Agreement Notice of 2025 Restricted Stock Unit Award Participant: David M. Feinberg You have been awarded the following equity grant of Restricted Stock Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached Restricted Stock Unit

2026 Ameren Short-Term Incentive Plan Plan Summary Effective January 1, 2026

Exhibit 10.20 2026 Ameren Short-Term Incentive Plan Plan Summary Effective January 1, 2026 1 2 Summary The Ameren Short-Term Incentive Plan (“STIP”) is intended to reward eligible Officers for their contributions to Ameren’s success. The STIP rewards Officers for results in the following categories: financial performance, safety, operational performance, customer, and individual performance during

2026 BASE SALARY TABLE FOR NAMED EXECUTIVE OFFICERS

Exhibit 10.22 2026 BASE SALARY TABLE FOR NAMED EXECUTIVE OFFICERS The 2026 annual base salaries of the following Named Executive Officers of Ameren Corporation (“Ameren”), Union Electric Company (“UE”) and Ameren Illinois Company (“AIC”) (which officers are employed by Ameren and/or an Ameren subsidiary as of February 18, 2026, and were determined to the extent applicable by reference to the Amere

SCHEDULE I CHANGE OF CONTROL SEVERANCE PLAN PARTICIPANTS EFFECTIVE JANUARY 1, 2026

Exhibit 10.25 SCHEDULE I CHANGE OF CONTROL SEVERANCE PLAN PARTICIPANTS EFFECTIVE JANUARY 1, 2026 Benefit Level - 3 Lindgren, Mark C. * Moehn, Michael * Lyons, Martin J. * Singh, Leonard P. Benefit Level - 2 Schukar, Shawn E. * Shaw, Theresa A. * Eligible for excise tax gross-up provisions (for Officers effective before October 1, 2009)

2025 Restricted Stock Unit Award Agreement

Exhibit 10.46 2025 Restricted Stock Unit Award Agreement Notice of 2025 Restricted Stock Unit Award Participant: David M. Feinberg You have been awarded the following equity grant of Restricted Stock Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached Restricted Stock Unit

SUBSIDIARIES OF AMEREN CORPORATION AT DECEMBER 31, 2025 Name State or Jurisdiction of Organization Ameren Corporation Missouri Ameren Development Company Missouri Missouri Central Railroad Company Delaware QST Enterprises Inc. Illinois Ameren EIP Inv

Exhibit 21.1 SUBSIDIARIES OF AMEREN CORPORATION AT DECEMBER 31, 2025 Name State or Jurisdiction of Organization Ameren Corporation Missouri Ameren Development Company Missouri Missouri Central Railroad Company Delaware QST Enterprises Inc. Illinois Ameren EIP Investment, LLC Delaware Ameren Accelerator Investments, LLC Delaware AmerenEnergy Medina Valley Cogen, L.L.C. Illinois Ameren Transmission

Ameren Corporation Severance Plan for Ameren Officers

Exhibit 10.47 Ameren Corporation Severance Plan for Ameren Officers Plan and Summary Plan Description Amended and Restated Effective January 1, 2026 1 Table of Contents 2 Introduction The Ameren Corporation Severance Plan for Ameren Officers (herein referred to as the “Plan”) is sponsored by Ameren Corporation and is offered to Officers of Ameren Corporation and its participating subsidiaries (ref

SUBSIDIARIES OF AMEREN CORPORATION AT DECEMBER 31, 2025 Name State or Jurisdiction of Organization Ameren Corporation Missouri Ameren Development Company Missouri Missouri Central Railroad Company Delaware QST Enterprises Inc. Illinois Ameren EIP Inv

Exhibit 21.1 SUBSIDIARIES OF AMEREN CORPORATION AT DECEMBER 31, 2025 Name State or Jurisdiction of Organization Ameren Corporation Missouri Ameren Development Company Missouri Missouri Central Railroad Company Delaware QST Enterprises Inc. Illinois Ameren EIP Investment, LLC Delaware Ameren Accelerator Investments, LLC Delaware AmerenEnergy Medina Valley Cogen, L.L.C. Illinois Ameren Transmission

2026 Restricted Stock Unit Award Agreement

Exhibit 10.43 2026 Restricted Stock Unit Award Agreement RSU Annual Award Notice of 2026 Restricted Stock Unit Award Participant: Grant Date: You have been granted the following Restricted Stock Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached award agreement, referred t

POWER OF ATTORNEY

Exhibit 24.3 POWER OF ATTORNEY WHEREAS, AMEREN ILLINOIS COMPANY, an Illinois corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2025; and WHEREAS, the individual identified below is a director of the

BONUS AGREEMENT

Exhibit 10.45 BONUS AGREEMENT This Bonus Agreement (hereinafter “Agreement”) is entered into this 13th day of November 2025, by and between David M. Feinberg (“Employee”) and Ameren Services Company (“Ameren Services”), a Missouri corporation, on behalf of itself and its parents, subsidiaries and affiliates (collectively, “Ameren” or “Company”) (Employee and Ameren or Company collectively, “Partie

2026 Performance Share Unit Award Agreement

Exhibit 10.41 2026 Performance Share Unit Award Agreement PSU Award - TSR Notice of 2026 Performance Share Unit Award (TSR) Participant: Grant Date: You have been granted the following Performance Share Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached award agreement, re

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the fiscal year ended December 31, 2025 OR ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number Exact name of regi

FORMULA FOR DETERMINING 2026 TARGET PSU AND RSU AWARDS FORMULA FOR DETERMINING 2026 TARGET PERFORMANCE SHARE UNIT ("PSU") AND RESTRICTED STOCK UNIT ("RSU") AWARDS TO BE ISSUED TO NAMED EXECUTIVE OFFICERS

Exhibit 10.29 FORMULA FOR DETERMINING 2026 TARGET PSU AND RSU AWARDS FORMULA FOR DETERMINING 2026 TARGET PERFORMANCE SHARE UNIT ("PSU") AND RESTRICTED STOCK UNIT ("RSU") AWARDS TO BE ISSUED TO NAMED EXECUTIVE OFFICERS The target number of PSUs and RSUs to be issued to each Named Executive Officer listed below for 2026 will be determined in accordance with the following formula: 2026 Target Number

SUBSIDIARIES OF AMEREN CORPORATION AT DECEMBER 31, 2025 Name State or Jurisdiction of Organization Ameren Corporation Missouri Ameren Development Company Missouri Missouri Central Railroad Company Delaware QST Enterprises Inc. Illinois Ameren EIP Inv

Exhibit 21.1 SUBSIDIARIES OF AMEREN CORPORATION AT DECEMBER 31, 2025 Name State or Jurisdiction of Organization Ameren Corporation Missouri Ameren Development Company Missouri Missouri Central Railroad Company Delaware QST Enterprises Inc. Illinois Ameren EIP Investment, LLC Delaware Ameren Accelerator Investments, LLC Delaware AmerenEnergy Medina Valley Cogen, L.L.C. Illinois Ameren Transmission

2026 BASE SALARY TABLE FOR NAMED EXECUTIVE OFFICERS

Exhibit 10.22 2026 BASE SALARY TABLE FOR NAMED EXECUTIVE OFFICERS The 2026 annual base salaries of the following Named Executive Officers of Ameren Corporation (“Ameren”), Union Electric Company (“UE”) and Ameren Illinois Company (“AIC”) (which officers are employed by Ameren and/or an Ameren subsidiary as of February 18, 2026, and were determined to the extent applicable by reference to the Amere

SCHEDULE I CHANGE OF CONTROL SEVERANCE PLAN PARTICIPANTS EFFECTIVE JANUARY 1, 2026

Exhibit 10.25 SCHEDULE I CHANGE OF CONTROL SEVERANCE PLAN PARTICIPANTS EFFECTIVE JANUARY 1, 2026 Benefit Level - 3 Lindgren, Mark C. * Moehn, Michael * Lyons, Martin J. * Singh, Leonard P. Benefit Level - 2 Schukar, Shawn E. * Shaw, Theresa A. * Eligible for excise tax gross-up provisions (for Officers effective before October 1, 2009)

2026 Performance Share Unit Award Agreement

Exhibit 10.41 2026 Performance Share Unit Award Agreement PSU Award - TSR Notice of 2026 Performance Share Unit Award (TSR) Participant: Grant Date: You have been granted the following Performance Share Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached award agreement, re

BONUS AGREEMENT

Exhibit 10.45 BONUS AGREEMENT This Bonus Agreement (hereinafter “Agreement”) is entered into this 13th day of November 2025, by and between David M. Feinberg (“Employee”) and Ameren Services Company (“Ameren Services”), a Missouri corporation, on behalf of itself and its parents, subsidiaries and affiliates (collectively, “Ameren” or “Company”) (Employee and Ameren or Company collectively, “Partie

POWER OF ATTORNEY

Exhibit 24.1 POWER OF ATTORNEY WHEREAS, AMEREN CORPORATION, a Missouri corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2025; and WHEREAS, each of the individuals identified below is a director of

2026 Performance Share Unit Award Agreement

Exhibit 10.41 2026 Performance Share Unit Award Agreement PSU Award - TSR Notice of 2026 Performance Share Unit Award (TSR) Participant: Grant Date: You have been granted the following Performance Share Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached award agreement, re

2026 Performance Share Unit Award Agreement

Exhibit 10.42 2026 Performance Share Unit Award Agreement PSU Award- Energy Resource Development Notice of 2026 Performance Share Unit Award (Energy Resource Development) Participant: Grant Date: You have been granted the following Performance Share Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, t

2026 Performance Share Unit Award Agreement

Exhibit 10.42 2026 Performance Share Unit Award Agreement PSU Award- Energy Resource Development Notice of 2026 Performance Share Unit Award (Energy Resource Development) Participant: Grant Date: You have been granted the following Performance Share Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, t

POWER OF ATTORNEY

Exhibit 24.2 POWER OF ATTORNEY WHEREAS, UNION ELECTRIC COMPANY, a Missouri corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2025; and WHEREAS, each of the individuals identified below is a director

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the fiscal year ended December 31, 2025 OR ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number Exact name of regi

FORMULA FOR DETERMINING 2026 TARGET PSU AND RSU AWARDS FORMULA FOR DETERMINING 2026 TARGET PERFORMANCE SHARE UNIT ("PSU") AND RESTRICTED STOCK UNIT ("RSU") AWARDS TO BE ISSUED TO NAMED EXECUTIVE OFFICERS

Exhibit 10.29 FORMULA FOR DETERMINING 2026 TARGET PSU AND RSU AWARDS FORMULA FOR DETERMINING 2026 TARGET PERFORMANCE SHARE UNIT ("PSU") AND RESTRICTED STOCK UNIT ("RSU") AWARDS TO BE ISSUED TO NAMED EXECUTIVE OFFICERS The target number of PSUs and RSUs to be issued to each Named Executive Officer listed below for 2026 will be determined in accordance with the following formula: 2026 Target Number

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the fiscal year ended December 31, 2025 OR ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number Exact name of regi

2026 BASE SALARY TABLE FOR NAMED EXECUTIVE OFFICERS

Exhibit 10.22 2026 BASE SALARY TABLE FOR NAMED EXECUTIVE OFFICERS The 2026 annual base salaries of the following Named Executive Officers of Ameren Corporation (“Ameren”), Union Electric Company (“UE”) and Ameren Illinois Company (“AIC”) (which officers are employed by Ameren and/or an Ameren subsidiary as of February 18, 2026, and were determined to the extent applicable by reference to the Amere

POWER OF ATTORNEY

Exhibit 24.3 POWER OF ATTORNEY WHEREAS, AMEREN ILLINOIS COMPANY, an Illinois corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2025; and WHEREAS, the individual identified below is a director of the

2026 Ameren Short-Term Incentive Plan Plan Summary Effective January 1, 2026

Exhibit 10.20 2026 Ameren Short-Term Incentive Plan Plan Summary Effective January 1, 2026 1 2 Summary The Ameren Short-Term Incentive Plan (“STIP”) is intended to reward eligible Officers for their contributions to Ameren’s success. The STIP rewards Officers for results in the following categories: financial performance, safety, operational performance, customer, and individual performance during

2025 Special Restricted Stock Unit Award Agreement October 9, 2025

Exhibit 10.44 Participant: Theresa Shaw You have been awarded the following special equity grant of Restricted Stock Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached Special Restricted Stock Unit Award Agreement. Notice of 2025 Special Restricted Stock Unit Award Grant D

2026 Restricted Stock Unit Award Agreement

Exhibit 10.43 2026 Restricted Stock Unit Award Agreement RSU Annual Award Notice of 2026 Restricted Stock Unit Award Participant: Grant Date: You have been granted the following Restricted Stock Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached award agreement, referred t

2026 Restricted Stock Unit Award Agreement

Exhibit 10.43 2026 Restricted Stock Unit Award Agreement RSU Annual Award Notice of 2026 Restricted Stock Unit Award Participant: Grant Date: You have been granted the following Restricted Stock Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached award agreement, referred t

2025 Special Restricted Stock Unit Award Agreement October 9, 2025

Exhibit 10.44 Participant: Theresa Shaw You have been awarded the following special equity grant of Restricted Stock Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached Special Restricted Stock Unit Award Agreement. Notice of 2025 Special Restricted Stock Unit Award Grant D

POWER OF ATTORNEY

Exhibit 24.1 POWER OF ATTORNEY WHEREAS, AMEREN CORPORATION, a Missouri corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2025; and WHEREAS, each of the individuals identified below is a director of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 6, 2026 AMEREN CORPORATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 6, 2026 AMEREN CORPORATION (Exact Name of Registrant as Specified in Charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Numb

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Exhibit 99.1 1901 Chouteau Avenue : St. Louis, MO 63103 : Ameren.com Contacts Media Ameren Communications 314.554.2182 [email protected] Financial Analysts and Institutional Investors Andrew Kirk 314.554.3942 [email protected] For Immediate Release Tim Rausch joins Ameren board of directors ST. LOUIS (Feb. 9, 2026) — Ameren Corporation (NYSE: AEE) announced today that Timothy S. Rausch has

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 12, 2025 AMEREN CORPORAT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 12, 2025 AMEREN CORPORATION (Exact Name of Registrant as Specified in Charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Num

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Exhibit 99.1 1901 Chouteau Avenue : St. Louis, MO 63103 : Ameren.com Contacts: Media Ameren Communications 314.554.2182 [email protected] Financial Analysts and Institutional Investors Andrew Kirk 314.554.3942 [email protected] FOR IMMEDIATE RELEASE Jamie Engstrom joins Ameren board of directors ST. LOUIS (Dec. 15, 2025) – Ameren Corporation (NYSE: AEE) announced today that Jamie L. Engstro

AMENDED AND RESTATED CREDIT AGREEMENT DATED AS OF DECEMBER 10, 2025, AMEREN CORPORATION AMEREN illinois company as Borrowers, THE LENDERS FROM TIME TO TIME PARTY HERETO JPMORGAN CHASE BANK, N.A. as Administrative Agent JPMorgan ChaSe Bank, N.A., BARC

EXHIBIT 10.2 EXECUTION VERSION AMENDED AND RESTATED CREDIT AGREEMENT DATED AS OF DECEMBER 10, 2025, among AMEREN CORPORATION and AMEREN illinois company as Borrowers, THE LENDERS FROM TIME TO TIME PARTY HERETO and JPMORGAN CHASE BANK, N.A. as Administrative Agent JPMorgan ChaSe Bank, N.A., BARCLAYS BANK PLC, MUFG Bank, LTD., BOFA SECURITIES, INC., MIZUHO BANK, LTD. and wells fargo SECURITIES, LLC,

AMENDED AND RESTATED CREDIT AGREEMENT DATED AS OF DECEMBER 10, 2025, AMEREN CORPORATION UNION ELECTRIC company as Borrowers, THE LENDERS FROM TIME TO TIME PARTY HERETO

EXHIBIT 10.1 EXECUTION VERSION AMENDED AND RESTATED CREDIT AGREEMENT DATED AS OF DECEMBER 10, 2025, among AMEREN CORPORATION and UNION ELECTRIC company as Borrowers, THE LENDERS FROM TIME TO TIME PARTY HERETO and JPMORGAN CHASE BANK, N.A. as Administrative Agent JPMorgan ChaSe Bank, N.A., BARCLAYS BANK PLC, MUFG Bank, LTD., BOFA SECURITIES, INC., Mizuho bank, ltd. and wells fargo SECURITIES, LLC,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 10, 2025

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 10, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 24, 2025

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 24, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the Quarterly Period Ended September 30, 2025 OR ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number Exact nam

AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts)

Exhibit 99.2 AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts) Three Months Ended September 30, Nine Months Ended September 30, 2025 2024 2025 2024 Operating Revenues: Electric $ 2,563 $ 2,035 $ 6,223 $ 4,920 Natural gas 136 138 794 762 Total operating revenues 2,699 2,173 7,017 5,682 Operating Expenses: Fuel and purchased power 768 499 2,

Ameren Announces Third Quarter 2025 Results

NEWS RELEASE 1901 Chouteau Avenue: St. Louis, MO 63103: Ameren.com Contacts: Media Financial Analysts and Institutional Investors Ameren Communications Andrew Kirk 314.554.2182 314.554.3942 [email protected] [email protected] For Immediate Release Ameren Announces Third Quarter 2025 Results •Third Quarter GAAP Diluted Earnings Per Share (EPS) were $2.35 in 2025 vs. Third Quarter GAAP EPS of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 5, 2025 AMEREN CORPORATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 5, 2025 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File

# # #

Exhibit 99.1 Contacts: Media Ameren Communications 314.554.2182 [email protected] Financial Analysts and Institutional Investors Andrew Kirk 314.554.3942 [email protected] FOR IMMEDIATE RELEASE Ameren Corporation announces leadership changes Moehn, Singh, Smith promoted to new roles ST. LOUIS (Oct. 14, 2025) – Ameren Corporation (NYSE: AEE) today announced organizational changes designed to

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): October 14, 2025 AMEREN CORPORATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): October 14, 2025 AMEREN CORPORATION (Exact Name of Registrant as Specified in Charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Numb

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): October 2, 2025 AMEREN CORPORATIO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): October 2, 2025 AMEREN CORPORATION (Exact Name of Registrant as Specified in Charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Numbe

Ameren Illinois Company First Mortgage Bonds due 2055 Underwriting Agreement

Exhibit 1.1 Ameren Illinois Company First Mortgage Bonds due 2055 Underwriting Agreement September 15, 2025 KeyBanc Capital Markets Inc. TD Securities (USA) LLC U.S. Bancorp Investments, Inc. As Representatives of the several Underwriters named in Schedule I to the applicable Pricing Agreement c/o  KeyBanc Capital Markets Inc. 127 Public Square Cleveland, Ohio 44114 TD Securities (USA) LLC 1 Vande

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): September 26, 2025

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): September 26, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 7, 2025 AMEREN CORPORATION

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 7, 2025 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State of other jurisdiction of incorporation) (Commission File Nu

Up to $1,482,210,000 Common Stock

TABLE OF CONTENTS  Filed Pursuant to Rule 424(b)(5)  Registration Statement No. 333-274977 PROSPECTUS SUPPLEMENT (To Prospectus dated October 13, 2023) Up to $1,482,210,000 Common Stock We have entered into a sales agreement (as amended, the “sales agreement”) with Barclays Capital Inc., BofA Securities, Inc., Goldman Sachs & Co. LLC, J.P. Morgan Securities LLC, Mizuho Securities USA LLC, Morgan S

Security Type

Calculation of Filing Fee Tables S-3 AMEREN CORP Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid 1 Equity Ameren Corporation Common Stock, $.

Ameren Corporation Common Stock, $.01 Par Value Per Share First Amendment to Equity Distribution Sales Agreement

Exhibit 1 Ameren Corporation Common Stock, $.01 Par Value Per Share First Amendment to Equity Distribution Sales Agreement August 7, 2025 Barclays Capital Inc. 745 7th Avenue New York, New York 10019 BofA Securities, Inc. One Bryant Park New York, New York 10036 Goldman Sachs & Co. LLC 200 West Street New York, New York 10282 J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179 M

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the Quarterly Period Ended June 30, 2025 OR ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number Exact name of

Ameren Announces Second Quarter 2025 Results

NEWS RELEASE 1901 Chouteau Avenue: St. Louis, MO 63103: Ameren.com Contacts: Media Financial Analysts and Institutional Investors Anthony Paraino Andrew Kirk 314.554.2182 314.554.3942 [email protected] [email protected] For Immediate Release Ameren Announces Second Quarter 2025 Results •Second Quarter Diluted Earnings Per Share were $1.01 in 2025 vs. $0.97 in 2024 •Reaffirm 2025 Diluted EPS Guida

Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): July 31, 2025 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Num

AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts)

Exhibit 99.2 AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts) Three Months Ended June 30, Six Months Ended June 30, 2025 2024 2025 2024 Operating Revenues: Electric $ 2,038 $ 1,521 $ 3,660 $ 2,885 Natural gas 183 172 658 624 Total operating revenues 2,221 1,693 4,318 3,509 Operating Expenses: Fuel and purchased power 794 327 1,296 655 Nat

UNITED STATES SECURITIES AND EXCHANGE COMMISISION WASHINGTON, DC 20549 FORM 11-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISISION WASHINGTON, DC 20549 FORM 11-K ☒ ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from      to      COMMISSION FILE NUMBER 1-14756 A.

Underwriting Agreement, dated May 12, 2025, among Ameren, the Underwriters, the Forward Purchasers and the Forward Sellers.

  Exhibit 1   Ameren Corporation   Common Stock, $.01 Par Value Per Share   Underwriting Agreement   May 12, 2025   Goldman Sachs & Co. LLC 200 West Street New York, New York 10282   J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179   Barclays Capital Inc. 745 Seventh Avenue New York, New York 10019   Wells Fargo Securities, LLC 500 West 33rd Street, 14th Floor New York, New Y

Additional Forward Sale Agreement, dated May 13, 2025, between Ameren and Barclays Bank PLC, as a Forward Purchaser

Exhibit 10.7 May 13, 2025 To: Ameren Corporation 1901 Chouteau Avenue St. Louis, Missouri 63103 From: Barclays Bank PLC 1 Churchill Place London E14 5HP United Kingdom Telephone: +44 (0)20 7623 2323 c/o Barclays Capital Inc. as Agent for Barclays Bank PLC 745 Seventh Avenue New York, NY 10019 Telephone: +1 212 526 7000 Dear Sirs, The purpose of this letter agreement (this “Confirmation”) is to con

Additional Forward Sale Agreement, dated May 13, 2025, between Ameren and JPMorgan Chase Bank, National Association, as a Forward Purchaser

Exhibit 10.6 May 13, 2025 To: Ameren Corporation 1901 Chouteau Avenue St. Louis, Missouri 63103 From: JPMorgan Chase Bank, National Association New York Branch 383 Madison Avenue New York, NY 10179 Dear Sirs, The purpose of this letter agreement (this “Confirmation”) is to confirm the terms and conditions of the transaction entered into between us on the Trade Date specified below (the “Transactio

Additional Forward Sale Agreement, dated May 13, 2025, between Ameren and Goldman Sachs & Co. LLC, as a Forward Purchaser

Exhibit 10.5 GOLDMAN SACHS & CO. LLC | 200 WEST STREET | NEW YORK, NEW YORK 10282-2198 | TEL: 212-902-1000 May 13, 2025 To: Ameren Corporation 1901 Chouteau Avenue St. Louis, Missouri 63103 Dear Sirs, The purpose of this letter agreement (this “Confirmation”) is to confirm the terms and conditions of the transaction entered into between us on the Trade Date specified below (the “Transaction”). Thi

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 12, 2025 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State of other jurisdiction of incorporation) (Commission File Numb

Forward Sale Agreement, dated May 12, 2025, between Ameren and Wells Fargo Bank, National Association, as a Forward Purchaser

Exhibit 10.4 May 12, 2025 To: Ameren Corporation 1901 Chouteau Avenue St. Louis, Missouri 63103 From: Wells Fargo Bank, National Association 30 Hudson Yards New York, NY 10001-2170 Email: [email protected] Dear Sirs, The purpose of this letter agreement (this “Confirmation”) is to confirm the terms and conditions of the transaction entered into between us on the Trade

Forward Sale Agreement, dated May 12, 2025, between Ameren and Barclays Bank PLC, as a Forward Purchaser

Exhibit 10.3 May 12, 2025 To: Ameren Corporation 1901 Chouteau Avenue St. Louis, Missouri 63103 From: Barclays Bank PLC 1 Churchill Place London E14 5HP United Kingdom Telephone: +44 (0)20 7623 2323 c/o Barclays Capital Inc. as Agent for Barclays Bank PLC 745 Seventh Avenue New York, NY 10019 Telephone: +1 212 526 7000 Dear Sirs, The purpose of this letter agreement (this “Confirmation”) is to con

Forward Sale Agreement, dated May 12, 2025, between Ameren and JPMorgan Chase Bank, National Association, as a Forward Purchaser

Exhibit 10.2 May 12, 2025 To: Ameren Corporation 1901 Chouteau Avenue St. Louis, Missouri 63103 From: JPMorgan Chase Bank, National Association New York Branch 383 Madison Avenue New York, NY 10179 Dear Sirs, The purpose of this letter agreement (this “Confirmation”) is to confirm the terms and conditions of the transaction entered into between us on the Trade Date specified below (the “Transactio

Additional Forward Sale Agreement, dated May 13, 2025, between Ameren and Wells Fargo Bank, National Association, as a Forward Purchaser

Exhibit 10.8 May 13, 2025 To: Ameren Corporation 1901 Chouteau Avenue St. Louis, Missouri 63103 From: Wells Fargo Bank, National Association 30 Hudson Yards New York, NY 10001-2170 Email: [email protected] Dear Sirs, The purpose of this letter agreement (this “Confirmation”) is to confirm the terms and conditions of the transaction entered into between us on the Trade

Forward Sale Agreement, dated May 12, 2025, between Ameren and Goldman Sachs & Co. LLC, as a Forward Purchaser

Exhibit 10.1 GOLDMAN SACHS & CO. LLC | 200 WEST STREET | NEW YORK, NEW YORK 10282-2198 | TEL: 212-902-1000 May 12, 2025 To: Ameren Corporation 1901 Chouteau Avenue St. Louis, Missouri 63103 Dear Sirs, The purpose of this letter agreement (this “Confirmation”) is to confirm the terms and conditions of the transaction entered into between us on the Trade Date specified below (the “Transaction”). Thi

Table 1: Newly Registered and Carry Forward Securities

Calculation of Filing Fee Tables S-3 AMEREN CORP Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid 1 Equity Ameren Corporation's Common Stock, $.

5,550,416 Shares Common Stock

TABLE OF CONTENTS  Filed pursuant to Rule 424(b)(2)  Registration No. 333-274977 PROSPECTUS SUPPLEMENT (To Prospectus dated October 13, 2023) 5,550,416 Shares Common Stock The forward sellers referred to below are offering 5,550,416 shares of our common stock, $.01 par value per share. We have entered into forward sale agreements with each of Goldman Sachs & Co. LLC, JPMorgan Chase Bank, National

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 8, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14756 Am

SUBJECT TO COMPLETION, DATED MAY 12, 2025

TABLE OF CONTENTS The information contained in this preliminary prospectus supplement is not complete and may be changed.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the Quarterly Period Ended March 31, 2025 OR ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number Exact name of

Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 1, 2025 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Numbe

Ameren Announces First Quarter 2025 Results

NEWS RELEASE 1901 Chouteau Avenue: St. Louis, MO 63103: Ameren.com Contacts: Media Analysts Anthony Paraino Andrew Kirk 314.554.2182 314.554.3942 [email protected] [email protected] For Immediate Release Ameren Announces First Quarter 2025 Results •First Quarter GAAP Diluted Earnings Per Share were $1.07 in 2025 vs. $0.98 in 2024 •First Quarter Adjusted (Non-GAAP) Diluted Earnings Per Share were

AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts)

Exhibit 99.2 AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts) Three Months Ended March 31, 2025 2024 Operating Revenues: Electric $ 1,622 $ 1,364 Natural gas 475 452 Total operating revenues 2,097 1,816 Operating Expenses: Fuel and purchased power 502 328 Natural gas purchased for resale 169 151 Other operations and maintenance 485 470 De

U.S. Securities and Exchange Commission Washington, DC 20549 Notice of Exempt Solicitation Submitted Pursuant to Rule 14a-6(g)

U.S. Securities and Exchange Commission Washington, DC 20549 Notice of Exempt Solicitation Submitted Pursuant to Rule 14a-6(g) 1. Name of the Registrant: Ameren Corporation 2. Name of person relying on exemption: The Comptroller of the City of New York, on behalf of the New York City Employees’ Retirement System, the New York City Teachers’ Retirement Systems, and the New York City Police Pension

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Defin

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 22, 2025 AMEREN CORPORATION (Exact Name of Registrant as Specified in Charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Number

Supplemental Indenture, dated March 1, 2025, by and between Ameren Missouri and The Bank of New York Mellon, as successor trustee, relating to the 5.25% First Mortgage Bonds due 2035.

Exhibit 4.2 SUPPLEMENTAL INDENTURE DATED MARCH 1, 2025 UNION ELECTRIC COMPANY TO THE BANK OF NEW YORK MELLON, AS TRUSTEE (SUPPLEMENTAL TO THE INDENTURE OF MORTGAGE AND DEED OF TRUST DATED JUNE 15, 1937, AS AMENDED, EXECUTED BY UNION ELECTRIC COMPANY TO THE BANK OF NEW YORK MELLON, AS TRUSTEE) 5.25% First Mortgage Bonds due 2035 This instrument was prepared by Stephen C. Lee, Esq., Vice President,

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 4, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14756

Underwriting Agreement relating to the Bonds, dated March 26, 2025, between Ameren Missouri and the several underwriters named therein, for whom Goldman Sachs & Co. LLC, RBC Capital Markets, LLC, Scotia Capital (USA) Inc. and SMBC Nikko Securities America, Inc. are acting as representatives.

Exhibit 1 Union Electric Company First Mortgage Bonds due 2035 Underwriting Agreement March 26, 2025 Goldman Sachs & Co.

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 24, 2025 AMEREN CORPORATION (Exact Name of Registrant as Specified in Charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Number

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Defin

ARS

2024 ANNUAL REPORT POWERING GROWTH GROWTHFINANCIAL AMEREN CONSOLIDATED (In millions, except per share amounts and as noted) RESULTS OF OPERATIONS Operating revenues Operating expenses Operating income Net income attributable to Ameren common shareholders COMMON STOCK DATA Earnings per diluted share Dividends per common share Dividend yield (year-end) Market price per common share (year-end closing

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.   )

TABLE OF CONTENTS UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.   ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Defin

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 7, 2025 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Num

Global Notes.

Exhibit 4.4 REGISTERED REGISTERED THIS NOTE IS A GLOBAL NOTE REGISTERED IN THE NAME OF THE DEPOSITARY (REFERRED TO HEREIN) OR A NOMINEE THEREOF AND, UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE FOR THE INDIVIDUAL NOTES REPRESENTED HEREBY AS PROVIDED IN THE INDENTURE REFERRED TO BELOW, THIS NOTE MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE O

Underwriting Agreement, dated February 27, 2025, between Ameren and the several underwriters named therein, for whom Barclays Capital Inc., J.P. Morgan Securities LLC, Mizuho Securities USA LLC, MUFG Securities Americas Inc. and Wells Fargo Securities, LLC are acting as representatives.

Exhibit 1 Ameren Corporation $750,000,000 5.375% Senior Notes due 2035 Underwriting Agreement February 27, 2025 Barclays Capital Inc. 745 Seventh Avenue New York, New York 10019 J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179 Mizuho Securities USA LLC 1271 Avenue of the Americas New York, New York 10020 MUFG Securities Americas Inc. 1221 Avenue of the Americas, 6th Floor New

Ameren Indenture Company Order, dated March 7, 2025, establishing the 5.375% Senior Notes due 2035

Exhibit 4.3 AMEREN CORPORATION Company Order March 7, 2025 The Bank of New York Mellon Trust Company, N.A., as Trustee 311 S. Wacker Drive Suite 6200B, Mailbox #44 Chicago, Illinois 60606 Re:          5.375% Senior Notes due 2035 Ladies and Gentlemen: Application is hereby made to The Bank of New York Mellon Trust Company, N.A., a national banking association, as successor trustee (the “Trustee”),

Underwriting Agreement relating to the Bonds, dated February 24, 2025, between Ameren Illinois and the several underwriters named therein, for whom BNY Mellon Capital Markets, LLC, BofA Securities, Inc., Morgan Stanley & Co. LLC and Truist Securities, Inc. are acting as representatives.

Exhibit 1.1 Ameren Illinois Company First Mortgage Bonds due 2055 Underwriting Agreement February 24, 2025 BNY Mellon Capital Markets, LLC BofA Securities, Inc. Morgan Stanley & Co. LLC Truist Securities, Inc. As Representatives of the several Underwriters named in Schedule I to the applicable Pricing Agreement  c/o BNY Mellon Capital Markets, LLC 240 Greenwich Street, 3W New York, New York 10286

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 26, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14

Supplemental Indenture, dated as of February 1, 2025, by and between Ameren Illinois and The Bank of New York Mellon Trust Company, N.A., as successor trustee, relating to the Bonds.

Exhibit 4.2 WHEN RECORDED MAIL TO: Ameren Illinois Company Jonathan T. Shade One Ameren Plaza (MC 1310) 1901 Chouteau Avenue St. Louis, MO 63103 AMEREN ILLINOIS COMPANY (SUCCESSOR TO ILLINOIS POWER COMPANY) TO THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. AS SUCCESSOR TRUSTEE TO HARRIS TRUST AND SAVINGS BANK SUPPLEMENTAL INDENTURE DATED AS OF FEBRUARY 1, 2025 TO GENERAL MORTGAGE INDENTURE AND DE

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 3, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14756

$750,000,000 5.375% Senior Notes due 2035

TABLE OF CONTENTS   Filed pursuant to Rule 424(b)(2)  Registration No. 333-274977 PROSPECTUS SUPPLEMENT (To Prospectus dated October 13, 2023) $750,000,000 5.375% Senior Notes due 2035 Ameren Corporation is offering $750,000,000 principal amount of its 5.375% Senior Notes due 2035, referred to in this prospectus supplement as the “senior notes.” The senior notes will mature on March 15, 2035. We w

Table 1: Newly Registered and Carry Forward Securities

Calculation of Filing Fee Tables S-3 AMEREN CORP Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid 1 Debt Ameren Corporation's 5.

SUBJECT TO COMPLETION, DATED FEBRUARY 27, 2025

TABLE OF CONTENTS The information contained in this preliminary prospectus supplement is not complete and may be changed.

Filed Pursuant to Rule 433

Filed Pursuant to Rule 433 Registration No. 333-274977 Ameren Corporation Pricing Term Sheet February 27, 2025 Issue: 5.375% Senior Notes due 2035 (the “Notes”) Principal Amount: $750,000,000 Coupon (Interest Rate): 5.375% per annum Maturity Date: March 15, 2035 Benchmark Treasury: 4.625% due February 15, 2035 Benchmark Treasury Price: 102-20 Benchmark Treasury Yield: 4.298% Spread to Benchmark Tr

*2025 Base Salary Table for Named Executive Officers

Exhibit 10.19 2025 BASE SALARY TABLE FOR NAMED EXECUTIVE OFFICERS The 2025 annual base salaries of the following Named Executive Officers of Ameren Corporation (“Ameren”), Union Electric Company (“UE”) and Ameren Illinois Company (“AIC”) (which officers are employed by Ameren and/or an Ameren subsidiary as of February 18, 2025, and were determined to the extent applicable by reference to the Amere

Subsidiaries of Ameren

Exhibit 21.1 SUBSIDIARIES OF AMEREN CORPORATION AT DECEMBER 31, 2024 Name State or Jurisdiction of Organization Ameren Corporation Missouri Ameren Development Company Missouri Missouri Central Railroad Company Delaware QST Enterprises Inc. Illinois Ameren EIP Investment, LLC Delaware Ameren Accelerator Investments, LLC Delaware AmerenEnergy Medina Valley Cogen, L.L.C. Illinois Ameren Transmission

*Form of Performance Share Unit Award Agreement (Clean Energy Transition metric) for awards issued in 2025 pursuant to 2022 Omnibus Incentive Compensation Plan

PSU Award- Clean Energy Metric 305903566v.2 Exhibit 10.48 2025 Performance Share Unit Award Agreement Notice of 2025 Performance Share Unit Award (Clean Energy Transition) Participant: Grant Date: You have been granted the following Performance Share Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time,

Powers of Attorney with respect to Ameren

Exhibit 24.1 POWER OF ATTORNEY WHEREAS, AMEREN CORPORATION, a Missouri corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2024; and WHEREAS, each of the individuals identified below is a director of

*Revised Schedule I to Second Amended and Restated Ameren Change of Control Severance Plan, as amended

Exhibit 10.22 SCHEDULE I CHANGE OF CONTROL SEVERANCE PLAN PARTICIPANTS EFFECTIVE DECEMBER 13, 2024 Benefit Level1 - 3 Birk, Mark C. Moehn, Michael Diya, Fadi Nwamu, Chonda * Lyons, Martin J. Singh, Leonard * Benefit Level1 - 2 Schukar, Shawn E. * Not eligible for excise tax gross-up provisions (for new officers effective on or after October 1, 2009) 1 Severance benefits include: •Cash severance, d

*Form of Performance Share Unit Award Agreement (Relative Total Shareholder Return metric) for awards issued in 2025 pursuant to 2022 Omnibus Incentive Compensation Plan

PSU Award - TSR Exhibit 10.47 2025 Performance Share Unit Award Agreement Notice of 2025 Performance Share Unit Award (TSR) Participant: Grant Date: You have been granted the following Performance Share Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached award agreement, re

Powers of Attorney with respect to Ameren Illinois

Exhibit 24.3 POWER OF ATTORNEY WHEREAS, AMEREN ILLINOIS COMPANY, an Illinois corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2024; and WHEREAS, each of the individuals identified below is a direct

Ameren Corporation Insider Trading Policy

Exhibit 19.1 Ameren Corporation Insider Trading Policy I.Purpose Ameren Corporation (including its direct and indirect subsidiaries, “Ameren” or the “Company”) has adopted this Insider Trading Policy (this “Policy”) to promote compliance with applicable laws that prohibit certain persons who are aware of Material Nonpublic Information (as defined below) about a company from: (i) trading in securit

*2025 Ameren Short-Term Incentive Plan

EXHIBIT 10.15 2025 Ameren Short-Term Incentive Plan Plan Summary Effective January 1, 2025 1 EXHIBIT 10.15 2 EXHIBIT 10.15 Summary The Ameren Short-Term Incentive Plan (“STIP”) is intended to reward eligible Officers for their contributions to Ameren’s success. The STIP rewards Officers for results in the following categories: financial performance, safety, operational performance, customer, econo

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the fiscal year ended December 31, 2024 OR ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number Exact name of regi

“Form of Restrictive Stock Unit Award Agreement for awards issued in 2025 pursuant to 2022 Omnibus Incentive Compensation Plan

RSU CEO Award 90286995v.6 Exhibit 10.49 2025 Restricted Stock Unit Award Agreement 59961097v.2 90286995v.6 Notice of 2025 Restricted Stock Unit Award Participant: Grant Date: You have been granted the following Restricted Stock Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the att

*Formula for Determining 2025 Target Performance Share Unit and Restricted Stock Unit Awards to be Issued to Named Executive Officers

Exhibit 10.29 FORMULA FOR DETERMINING 2025 TARGET PSU AND RSU AWARDS FORMULA FOR DETERMINING 2025 TARGET PERFORMANCE SHARE UNIT ("PSU") AND RESTRICTED STOCK UNIT ("RSU") AWARDS TO BE ISSUED TO NAMED EXECUTIVE OFFICERS The target number of PSUs and RSUs to be issued to each Named Executive Officer listed below for 2025 will be determined in accordance with the following formula: 2025 Target Number

Powers of Attorney with respect to Ameren Missouri

Exhibit 24.2 POWER OF ATTORNEY WHEREAS, UNION ELECTRIC COMPANY, a Missouri corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2024; and WHEREAS, each of the individuals identified below is a director

AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts)

Exhibit 99.2 AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts) Three Months Ended December 31, Year Ended December 31, 2024 2023 2024 2023 Operating Revenues: Electric $ 1,620 $ 1,343 $ 6,540 $ 6,439 Natural gas 321 275 1,083 1,061 Total operating revenues 1,941 1,618 7,623 7,500 Operating Expenses: Fuel and purchased power 527 294 1,681 1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 13, 2025 AMEREN CORPORAT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 13, 2025 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File

Ameren Announces 2024 Results, Affirms Guidance for 2025 Earnings and Issues Long-Term Growth Guidance

Exhibit 99.1 NEWS RELEASE 1901 Chouteau Avenue: St. Louis, MO 63103: Ameren.com Contacts Media Investors Tony Paraino Andrew Kirk 314.554.2182 314.554.3942 [email protected] [email protected] For Immediate Release Ameren Announces 2024 Results, Affirms Guidance for 2025 Earnings and Issues Long-Term Growth Guidance •2024 GAAP Diluted Earnings Per Share (EPS) were $4.42 vs. $4.38 in 2023 •2024 Adj

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): January 30, 2025 AMEREN CORPORATION (Exact Name of Registrant as Specified in Charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Numb

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 19, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14

###

Exhibit 99.1 1901 Chouteau Avenue : St. Louis, MO 63103 : Ameren.com Contacts: Media Ameren Communications 314.554.2182 [email protected] Analysts Andrew Kirk 314.554.3942 [email protected] FOR IMMEDIATE RELEASE Steven Vondran joins Ameren board of directors ST. LOUIS (Dec. 16, 2024) — Ameren Corporation (NYSE: AEE) announced today that Steven O. Vondran has been elected to the Ameren board

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 13, 2024 AMEREN CORPORATION (Exact Name of Registrant as Specified in Charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Num

AEE / Ameren Corporation / T. Rowe Price Investment Management, Inc. Passive Investment

SC 13G/A 1 aee13gasep24.txt UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1) AMEREN CORPORATION (Name of Issuer) COMMON STOCK (Title of Class of Securities) 023608102 (CUSIP NUMBER) September 30, 2024 (Date of Event which Requires Filing of Statement) Check the appropriate box to designate the Rule purs

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the Quarterly Period Ended September 30, 2024 OR ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number Exact nam

Note Purchase Agreement, dated as of August 30, 2024, between Ameren Transmission Company of Illinois and the several purchasers named therein.

Exhibit 4.1 Execution Version Ameren Transmission Company of Illinois $140,000,000 $70,000,000 5.17% Senior Notes, Series A, due September 1, 2039 and $70,000,000 5.42% Senior Notes, Series B, due September 1, 2053 Note Purchase Agreement Dated as of August 30, 2024 Table of Contents Section Heading Page Section 2. Sale and Purchase of Notes 1 Section 3. Closing 2 Section 4. Conditions to Closing

Ameren Announces Third Quarter 2024 Results

Exhibit 99.1 NEWS RELEASE 1901 Chouteau Avenue: St. Louis, MO 63103: Ameren.com Contacts: Media Analysts Anthony Paraino Andrew Kirk 314.554.2182 314.554.3942 [email protected] [email protected] For Immediate Release Ameren Announces Third Quarter 2024 Results •Third Quarter GAAP Diluted Earnings Per Share (EPS) were $1.70 in 2024 vs. $1.87 in 2023 •Third Quarter Adjusted (Non-GAAP) Diluted Earni

Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 6, 2024 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File

AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts)

Exhibit 99.2 AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts) Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Operating Revenues: Electric $ 2,035 $ 1,921 $ 4,920 $ 5,096 Natural gas 138 139 762 786 Total operating revenues 2,173 2,060 5,682 5,882 Operating Expenses: Fuel and purchased power 499 430 1,

AEE / Ameren Corporation / STATE STREET CORP Passive Investment

SC 13G/A 1 AmerenCorp.htm SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* AMEREN CORP (Name of Issuer) COMMON STOCK (Title of Class of Securities) 023608102 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of This Statement) Check the appropriate box to designate the rule pursuant to which this

Supplemental Indenture, dated September 1, 2024, by and between Ameren Missouri and The Bank of New York Mellon, as successor trustee, relating to the 5.125% First Mortgage Bonds due 2055.

Exhibit 4.2 SUPPLEMENTAL INDENTURE DATED SEPTEMBER 1, 2024 UNION ELECTRIC COMPANY TO THE BANK OF NEW YORK MELLON, AS TRUSTEE (SUPPLEMENTAL TO THE INDENTURE OF MORTGAGE AND DEED OF TRUST DATED JUNE 15, 1937, AS AMENDED, EXECUTED BY UNION ELECTRIC COMPANY TO THE BANK OF NEW YORK MELLON, AS TRUSTEE) 5.125% First Mortgage Bonds due 2055 This instrument was prepared by Chonda J. Nwamu, Esq., Executive

Underwriting Agreement relating to the Bonds, dated September 30, 2024, between Ameren Missouri and the several underwriters named therein, for whom Barclays Capital Inc., BofA Securities, Inc., J.P. Morgan Securities LLC and Morgan Stanley & Co. LLC are acting as representatives.

Exhibit 1 Union Electric Company First Mortgage Bonds due 2055 Underwriting Agreement September 30, 2024 Barclays Capital Inc.

AEE / Ameren Corporation / PRICE T ROWE ASSOCIATES INC /MD/ Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 5) AMEREN CORPORATION (Name of Issuer) COMMON STOCK (Title of Class of Securities) 023608102 (CUSIP NUMBER) September 30, 2024 (Date of Event which Requires Filing of Statement) Check the appropriate box to designate the Rule pursuant to which this Schedule

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): October 7, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-1475

Ameren Corporation By-Laws, as amended effective August 9, 2024

Exhibit 3.1 AMEREN CORPORATION BY-LAWS As Amended Effective August 9, 2024 Article I Shareholders Section 1.                The annual meeting of the shareholders of Ameren Corporation (the "Company") shall be held on the second Thursday of May in each year (or if said day be a legal holiday, then on the next succeeding day not a legal holiday), at the registered office of the Company in the City

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 9, 2024 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Nu

Separation Agreement and General Release, effective April 5, 2024, between Bhavani Amirthalingam and Ameren Services Company

Exhibit 10.1 CONFIDENTIAL SEPARATION AGREEMENT AND GENERAL RELEASE This Confidential Separation Agreement and General Release (“Agreement”) is entered into by and between Bhavani Amirthalingam (“Employee”) and Ameren Services Company, a Missouri corporation, on behalf of itself and any parent company, subsidiary, division or affiliate entity (collectively, “Ameren”). RECITALS A.Employee has been e

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the Quarterly Period Ended June 30, 2024 OR ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number Exact name of

AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts)

Exhibit 99.2 AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts) Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Operating Revenues: Electric $ 1,521 $ 1,585 $ 2,885 $ 3,175 Natural gas 172 175 624 647 Total operating revenues 1,693 1,760 3,509 3,822 Operating Expenses: Fuel and purchased power 327 480 655 1,088 Nat

Ameren Announces Second Quarter 2024 Results

Exhibit 99.1 NEWS RELEASE 1901 Chouteau Avenue: St. Louis, MO 63103: Ameren.com Contacts: Media Analysts Anthony Paraino Andrew Kirk 314.554.2182 314.554.3942 [email protected] [email protected] For Immediate Release Ameren Announces Second Quarter 2024 Results •Second quarter Diluted Earnings Per Share were $0.97 in 2024 vs. $0.90 in 2023 •Guidance Range for 2024 Reaffirmed at $4.52 to $4.72 per

Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 1, 2024 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Nu

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 28, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14756

Underwriting Agreement relating to the Bonds, dated June 17, 2024, between Ameren Illinois and the several underwriters named therein, for whom Barclays Capital Inc., MUFG Securities Americas Inc., Scotia Capital (USA) Inc., TD Securities (USA) LLC and Wells Fargo Securities, LLC are acting as representatives.

Exhibit 1.1 Ameren Illinois Company First Mortgage Bonds due 2054 Underwriting Agreement June 17, 2024 Barclays Capital Inc. MUFG Securities Americas Inc. Scotia Capital (USA) Inc. TD Securities (USA) LLC Wells Fargo Securities, LLC As Representatives of the several Underwriters named in Schedule I to the applicable Pricing Agreement c/o Barclays Capital Inc. 745 Seventh Avenue New York, New York

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 27, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14756

Supplemental Indenture, dated as of June 1, 2024, by and between Ameren Illinois and The Bank of New York Mellon Trust Company, N.A., as successor trustee, relating to the Bonds.

Exhibit 4.2 WHEN RECORDED MAIL TO: Ameren Illinois Company Jonathan T. Shade One Ameren Plaza (MC 1310) 1901 Chouteau Avenue St. Louis, MO 63103 AMEREN ILLINOIS COMPANY (SUCCESSOR TO ILLINOIS POWER COMPANY) TO THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. AS SUCCESSOR TRUSTEE TO HARRIS TRUST AND SAVINGS BANK SUPPLEMENTAL INDENTURE DATED AS OF JUNE 1, 2024 TO GENERAL MORTGAGE INDENTURE AND DEED O

UNITED STATES SECURITIES AND EXCHANGE COMMISISION WASHINGTON, DC 20549 FORM 11-K ☒ ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023

UNITED STATES SECURITIES AND EXCHANGE COMMISISION WASHINGTON, DC 20549 FORM 11-K ☒ ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from       to       COMMISSION FILE NUMBER 1-14756 A.

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 20, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14756

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 20, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14756

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 9, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14756 Am

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the Quarterly Period Ended March 31, 2024 OR ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number Exact name of

Ameren Announces First Quarter 2024 Results

Exhibit 99.1 NEWS RELEASE 1901 Chouteau Avenue: St. Louis, MO 63103: Ameren.com Contacts: Media Analysts Anthony Paraino Andrew Kirk 314.554.2182 314.554.3942 [email protected] [email protected] For Immediate Release Ameren Announces First Quarter 2024 Results •First quarter Diluted Earnings Per Share were $0.98 in 2024 vs. $1.00 in 2023 •Guidance Range for 2024 Affirmed at $4.52 to $4.72 per Dil

AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts)

Exhibit 99.2 AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts) Three Months Ended March 31, 2024 2023 Operating Revenues: Electric $ 1,364 $ 1,590 Natural gas 452 472 Total operating revenues 1,816 2,062 Operating Expenses: Fuel and purchased power 328 608 Natural gas purchased for resale 151 208 Other operations and maintenance 470 448 De

Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 2, 2024 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Numbe

LETTER

United States securities and exchange commission logo April 18, 2024 Theresa Shaw Chief Accounting Officer Ameren Corporation 1901 Chouteau Avenue St.

* * *

April 10, 2024 Securities and Exchange Commission Division of Corporation Finance Office of Energy & Transportation 100 F Street, N.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Defin

Underwriting Agreement, dated March 25, 2024, between Ameren Missouri and the several underwriters named therein, for whom BNY Mellon Capital Markets, LLC, J.P. Morgan Securities LLC, Mizuho Securities USA LLC and U.S. Bancorp Investments, Inc. are acting as representatives.

Exhibit 1 Union Electric Company First Mortgage Bonds Underwriting Agreement March 25, 2024 BNY Mellon Capital Markets, LLC J.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 4, 2024

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 4, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14756

Supplemental Indenture, dated March 1, 2024, by and between Ameren Missouri and The Bank of New York Mellon, as successor trustee, relating to the 5.20% First Mortgage Bonds due 2034.

Exhibit 4.2 SUPPLEMENTAL INDENTURE DATED MARCH 1, 2024 UNION ELECTRIC COMPANY TO THE BANK OF NEW YORK MELLON, AS TRUSTEE (SUPPLEMENTAL TO THE INDENTURE OF MORTGAGE AND DEED OF TRUST DATED JUNE 15, 1937, AS AMENDED, EXECUTED BY UNION ELECTRIC COMPANY TO THE BANK OF NEW YORK MELLON, AS TRUSTEE) 5.20% First Mortgage Bonds due 2034 This instrument was prepared by Chonda J. Nwamu, Esq., Executive Vice

LETTER

United States securities and exchange commission logo March 27, 2024 Theresa Shaw Chief Accounting Officer Ameren Corporation 1901 Chouteau Avenue St.

ARS

RELIABLE 20 23 ANNUAL REPORTAMEREN CONSOLIDATED (In millions, except per share amounts and as noted) RESULTS OF OPERATIONS Operating revenues Operating expenses Operating income Net income attributable to Ameren common shareholders COMMON STOCK DATA Earnings per diluted share Dividends per common share Dividend yield (year-end) Market price per common share (year-end closing) Weighted average comm

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.    )

TABLE OF CONTENTS UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.    ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Defin

*Second Amendment to amended and restated Ameren Supplemental Retirement Plan, dated November 27, 2013

Exhibit 10.52 SECOND AMENDMENT TO THE AMEREN SUPPLEMENTAL RETIREMENT PLAN Amended and Restated Effective January 1, 2008 WHEREAS, Ameren Corporation ("Company") previously adopted the Ameren Supplemental Retirement Plan, as amended and restated effective January 1, 2008 (the "Plan"); and WHEREAS, the Company reserved the right to amend the Plan; and WHEREAS, the Company desires to amend the Plan t

*Form of Performance Share Unit Award Agreement (Clean Energy Transition metric) for awards issued in 2024 pursuant to 2022 Omnibus Incentive Compensation Plan

Exhibit 10.46 2024 Performance Share Unit Award Agreement PSU Award- Clean Energy Metric305903566v.2 Participant: Grant Date: You have been granted the following Performance Share Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached award agreement, referred to as Performanc

*Form of Performance Share Unit Award Agreement (Relative Total Shareholder Return metric) for awards issued in 2024 pursuant to 2022 Omnibus Incentive Compensation Plan

Exhibit 10.45 2024 Performance Share Unit Award Agreement PSU Award - TSR Participant: Grant Date: You have been granted the following Performance Share Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached award agreement, referred to as Performance Share Unit Award Agreemen

Powers of Attorney with respect to Ameren Missouri

Exhibit 24.2 POWER OF ATTORNEY WHEREAS, UNION ELECTRIC COMPANY, a Missouri corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2023; and WHEREAS, each of the individuals identified below is a director

Powers of Attorney with respect to Ameren Illinois

Exhibit 24.3 POWER OF ATTORNEY WHEREAS, AMEREN ILLINOIS COMPANY, an Illinois corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2023; and WHEREAS, each of the individuals identified below is a direct

*2024 Ameren Short-Term Incentive Plan

Exhibit 10.15 2024 Ameren Short-Term Incentive Plan Plan Summary Effective January 1, 2024 Contents Page Annual Performance Metrics 3 Definitions 4 Performance Achievement Levels 6 Base Award 6 Individual Performance Modifier 6 Individual Short-Term Incentive Payout 7 Confidential Information 9 Non-Solicitation 9 Impact on Incentive Award Payment 10 2 Summary The Ameren Short-Term Incentive Plan (

*Revised Schedule I to Second Amended and Restated Ameren Change of Control Severance Plan, as amended

Exhibit 10.22 SCHEDULE I CHANGE OF CONTROL SEVERANCE PLAN PARTICIPANTS EFFECTIVE DECEMBER 15, 2023 Benefit Level1 - 3 Birk, Mark C. Moehn, Michael Diya, Fadi Nwamu, Chonda * Lyons, Martin J. Singh, Leonard * Benefit Level1 - 2 Amirthalingam, Bhavani * * Not eligible for excise tax gross-up provisions (for new officers effective on or after October 1, 2009) 1 Severance benefits include: •Cash sever

Ameren Corporation Financial Restatement Compensation Recoupment Policy, as adopted August 10, 2023

Exhibit 97.1 AMEREN CORPORATION FINANCIAL RESTATEMENT COMPENSATION RECOUPMENT POLICY This Ameren Corporation Financial Restatement Compensation Recoupment Policy (“Policy”) has been adopted by the Human Resources Committee of the Board of Directors (the “Board”) of Ameren Corporation as of August 10, 2023. This Policy provides for the recoupment of certain executive compensation in the event of an

*Fifth Amendment to amended and restated Ameren Supplemental Retirement Plan, dated October 13, 2023

Exhibit 10.55 FIFTH AMENDMENT TO THE AMEREN SUPPLEMENTAL RETIREMENT PLAN Amended and Restated Effective January 1, 2008 WHEREAS, Ameren Corporation ("Company") previously adopted the Ameren Supplemental Retirement Plan, as amended and restated effective January 1, 2008 (the "Plan"), and as subsequently amended by the First Amendment to the Ameren Supplemental Retirement Plan, dated October 24, 200

*Third Amendment to amended and restated Ameren Supplemental Retirement Plan, dated January 5, 2015

Exhibit 10.53 Third Amendment to the Ameren Supplemental Retirement Plan Amended and Restated Effective January 1, 2008 WHEREAS, Ameren Corporation ("Company") previously adopted the Ameren Supplemental Retirement Plan, as amended and restated effective January 1, 2008 (the "Plan"); and WHEREAS, the Company reserved the right to amend the Plan; and WHEREAS, the Company desires to amend the Plan to

*Ameren’s Deferred Compensation Plan as amended and restated effective January 1, 2023

Exhibit 10.10 AMEREN DEFERRED COMPENSATION PLAN AND PARTICIPANT SUMMARY AMENDED AND RESTATED EFFECTIVE AS OF JANUARY 1, 2023 87100518v.8 AMEREN DEFERRED COMPENSATION PLAN As Amended and Restated Effective January 1, 2023 WHEREAS, Ameren Corporation amended and restated the Ameren Corporation Deferred Compensation Plan (“Plan”) effective as of January 1, 2010; and WHEREAS, Ameren Corporation reserv

*Performance-Based Restricted Share Unit Award Agreement, dated as of November 1, 2023, between Ameren and Michael L. Moehn

Exhibit 10.48 2023 Performance Based Restricted Stock Unit Award Agreement PSU Award- TSR Metric98060243v.3 Participant: Michael Moehn Grant Date: November 1, 2023 You have been granted the following Performance Based Restricted Stock Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and

Subsidiaries of Ameren

Exhibit 21.1 SUBSIDIARIES OF AMEREN CORPORATION AT DECEMBER 31, 2023 Name State or Jurisdiction of Organization Ameren Corporation Missouri Ameren Development Company Missouri Missouri Central Railroad Company Delaware QST Enterprises Inc. Illinois Ameren EIP Investment, LLC Delaware Ameren Accelerator Investments, LLC Delaware AmerenEnergy Medina Valley Cogen, L.L.C. Illinois Ameren Transmission

Powers of Attorney with respect to Ameren

Exhibit 24.1 POWER OF ATTORNEY WHEREAS, AMEREN CORPORATION, a Missouri corporation (herein referred to as the "Company"), is required to file with the Securities and Exchange Commission, under the provisions of the Securities Exchange Act of 1934, as amended, its annual report on Form 10-K for the year ended December 31, 2023; and WHEREAS, each of the individuals identified below is a director of

*2024 Base Salary Table for Named Executive Officers

Exhibit 10.19 2024 BASE SALARY TABLE FOR NAMED EXECUTIVE OFFICERS The 2024 annual base salaries of the following Named Executive Officers of Ameren Corporation (“Ameren”), Union Electric Company (“UE”) and Ameren Illinois Company (“AIC”) (which officers are employed by Ameren and/or an Ameren subsidiary as of February 16, 2024, and were determined to the extent applicable by reference to the Amere

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the fiscal year ended December 31, 2023 OR ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number Exact name of regi

*Formula for Determining 2024 Target Performance Share Unit and Restricted Stock Unit Awards to be Issued to Named Executive Officers

Exhibit 10.29 FORMULA FOR DETERMINING 2024 TARGET PSU AND RSU AWARDS FORMULA FOR DETERMINING 2024 TARGET PERFORMANCE SHARE UNIT ("PSU") AND RESTRICTED STOCK UNIT ("RSU") AWARDS TO BE ISSUED TO NAMED EXECUTIVE OFFICERS The target number of PSUs and RSUs to be issued to each Named Executive Officer listed below for 2024 will be determined in accordance with the following formula: 2024 Target Number

*Form of Restrictive Stock Unit Award Agreement for awards issued in 2024 pursuant to 2022 Omnibus Incentive Compensation Plan

Exhibit 10.47 2024 Restricted Stock Unit Award Agreement RSU Annual Award Notice of 2024 Restricted Stock Unit Award Participant: Grant Date: You have been granted the following Restricted Stock Units in accordance with the terms of the Ameren Corporation 2022 Omnibus Incentive Compensation Plan (as the same may be amended from time to time, the "Plan") and the attached award agreement, referred t

*Fourth Amendment to amended and restated Ameren Supplemental Retirement Plan, dated November 3, 2015

Exhibit 10.54 FOURTH AMENDMENT TO THE AMEREN SUPPLEMENTAL RETIREMENT PLAN Amended and Restated Effective January 1, 2008 WHEREAS, Ameren Corporation ("Company") previously adopted the Ameren Supplemental Retirement Plan, as amended and restated effective January 1, 2008 (the "Plan"); and WHEREAS, the Company reserved the right to amend the Plan; and WHEREAS, the Company desires to amend the Plan t

Ameren Announces 2023 Results and Issues Guidance for 2024 Earnings and Long-Term Growth

Exhibit 99.1 NEWS RELEASE 1901 Chouteau Avenue: St. Louis, MO 63103: Ameren.com Contacts Media Investors Tony Paraino Andrew Kirk 314.554.2182 314.554.3942 [email protected] [email protected] For Immediate Release Ameren Announces 2023 Results and Issues Guidance for 2024 Earnings and Long-Term Growth •2023 Diluted Earnings Per Share (EPS) were $4.38, Compared to $4.14 in 2022 •2024 Diluted EPS G

AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts)

Exhibit 99.2 AMEREN CORPORATION (AEE) CONSOLIDATED STATEMENT OF INCOME (Unaudited, in millions, except per share amounts) Three Months Ended December 31, Year Ended December 31, 2023 2022 2023 2022 Operating Revenues: Electric $ 1,343 $ 1,610 $ 6,439 $ 6,581 Natural gas 275 436 1,061 1,376 Total operating revenues 1,618 2,046 7,500 7,957 Operating Expenses: Fuel 91 97 514 473 Purchased power 203 4

Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 22, 2024 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File

AEE / Ameren Corporation / T. Rowe Price Investment Management, Inc. Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. ) AMEREN CORPORATION (Name of Issuer) COMMON STOCK (Title of Class of Securities) 023608102 (CUSIP NUMBER) December 31, 2023 (Date of Event which Requires Filing of Statement) Check the appropriate box to designate the Rule pursuant to which this Schedule is

AEE / Ameren Corporation / PRICE T ROWE ASSOCIATES INC /MD/ Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 4) AMEREN CORPORATION (Name of Issuer) COMMON STOCK (Title of Class of Securities) 023608102 (CUSIP NUMBER) December 31, 2023 (Date of Event which Requires Filing of Statement) Check the appropriate box to designate the Rule pursuant to which this Schedule i

AEE / Ameren Corporation / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SC 13G/A 1 tv0012-amerencorp.htm SCHEDULE 13G/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 14)* Name of issuer: Ameren Corp Title of Class of Securities: Common Stock CUSIP Number: 023608102 Date of Event Which Requires Filing of this Statement: December 29, 2023 Check the appropriate box to designate the rule pu

AEE / Ameren Corporation / STATE STREET CORP Passive Investment

SC 13G/A 1 AmerenCorp.txt UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 AMENDED FILING AMEREN CORP (NAME OF ISSUER) COMMON STOCK (TITLE OF CLASS OF SECURITIES) 023608102 (CUSIP NUMBER) 12/31/2023 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUANT TO WHICH T

AEE / Ameren Corporation / BlackRock Inc. Passive Investment

SC 13G/A 1 us0236081024012624.txt us0236081024012624.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 13) AMEREN CORPORATION - (Name of Issuer) Common Stock - (Title of Class of Securities) 023608102 - (CUSIP Number) December 31, 2023 - (Date of Event Which Requires Filing of this Statement) Check the appropriate bo

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): January 9, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-1475

Supplemental Indenture to the Ameren Missouri Mortgage dated January 1, 2024, for 5.25% First Mortgage Bonds due 2054

Exhibit 4.2 SUPPLEMENTAL INDENTURE DATED JANUARY 1, 2024 UNION ELECTRIC COMPANY TO THE BANK OF NEW YORK MELLON, AS TRUSTEE (SUPPLEMENTAL TO THE INDENTURE OF MORTGAGE AND DEED OF TRUST DATED JUNE 15, 1937, AS AMENDED, EXECUTED BY UNION ELECTRIC COMPANY TO THE BANK OF NEW YORK MELLON, AS TRUSTEE) 5.25% First Mortgage Bonds due 2054 This instrument was prepared by Chonda J. Nwamu, Esq., Executive Vic

Underwriting Agreement, dated January 3, 2024, between Ameren Missouri and the several underwriters named therein, for whom BofA Securities, Inc., RBC Capital Markets, LLC, SMBC Nikko Securities America, Inc. and Truist Securities, Inc. are acting as representatives.

Exhibit 1 Union Electric Company First Mortgage Bonds Underwriting Agreement January 3, 2024 BofA Securities, Inc.

Underwriting Agreement, dated December 18, 2023, between Ameren and the several underwriters named therein, for whom Barclays Capital Inc., Goldman Sachs & Co. LLC, J.P. Morgan Securities LLC, Morgan Stanley & Co. LLC and MUFG Securities Americas Inc. are acting as representatives.

Exhibit 1 Execution Version Ameren Corporation $700,000,000 5.00% Senior Notes due 2029 Underwriting Agreement December 18, 2023 Barclays Capital Inc. 745 Seventh Avenue New York, New York 10019 Goldman Sachs & Co. LLC 200 West Street New York, New York 10282 J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179 Morgan Stanley & Co. LLC 1585 Broadway, 29th Floor New York, New York

Ameren Indenture Company Order, dated December 21, 2023, establishing the 5.00% Senior Notes due 2029 (including the global note)

Exhibit 4.3 AMEREN CORPORATION Company Order December 21, 2023 The Bank of New York Mellon Trust Company, N.A., as Trustee 2 North LaSalle Street, Suite 700 Chicago, Illinois 60602 Re:         5.00% Senior Notes due 2029 Ladies and Gentlemen: Application is hereby made to The Bank of New York Mellon Trust Company, N.A., a national banking association, as successor trustee (the “Trustee”), under th

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 21, 2023 AMEREN CORPORAT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 21, 2023 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File

Global Notes.

Exhibit 4.4 REGISTERED REGISTERED THIS NOTE IS A GLOBAL NOTE REGISTERED IN THE NAME OF THE DEPOSITARY (REFERRED TO HEREIN) OR A NOMINEE THEREOF AND, UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE FOR THE INDIVIDUAL NOTES REPRESENTED HEREBY AS PROVIDED IN THE INDENTURE REFERRED TO BELOW, THIS NOTE MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE O

Calculation of Filing Fee Tables (1) Form 424(b)(2) (Form Type) Ameren Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities and Carry Forward Securities

Exhibit 107 Calculation of Filing Fee Tables (1) Form 424(b)(2) (Form Type) Ameren Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to Be Paid Debt Ameren Corporation’s 5.

$700,000,000 5.00% Senior Notes due 2029

TABLE OF CONTENTS  Filed pursuant to Rule 424(b)(2)  Registration No. 333-274977 PROSPECTUS SUPPLEMENT (To Prospectus dated October 13, 2023) $700,000,000 5.00% Senior Notes due 2029 Ameren Corporation is offering $700,000,000 principal amount of its 5.00% Senior Notes due 2029, referred to in this prospectus supplement as the “senior notes.” The senior notes will mature on January 15, 2029. We wi

SUBJECT TO COMPLETION, DATED DECEMBER 18, 2023

TABLE OF CONTENTS The information contained in this preliminary prospectus supplement is not complete and may be changed.

###

Exhibit 99.1 news release 1901 Chouteau Avenue : St. Louis, MO 63103 : Ameren.com Contacts: Media Ameren Communications 314.554.2182 [email protected] Analysts Andrew Kirk 314.554.3942 [email protected] For Immediate Release Kimberly Harris joins Ameren Board of Directors ST. LOUIS (Dec. 18, 2023) — The board of directors of Ameren Corporation (NYSE: AEE) announced today that Kimberly J. Ha

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 15, 2023 AMEREN CORPORATION (Exact Name of Registrant as Specified in Charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File Num

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 14, 2023 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14

Ameren Corporation Pricing Term Sheet December 18, 2023

Filed Pursuant to Rule 433 Registration No. 333-274977 Ameren Corporation Pricing Term Sheet December 18, 2023 Issue: 5.00% Senior Notes due 2029 (the “Notes”) Principal Amount: $700,000,000 Coupon (Interest Rate): 5.00% per annum Maturity Date: January 15, 2029 Benchmark Treasury: 4.375% due November 30, 2028 Benchmark Treasury Price: 101-28+ Benchmark Treasury Yield: 3.950% Spread to Benchmark T

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 16, 2023 Commission File Number Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number IRS Employer Identification Number 1-14

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 20, 2023 AMEREN CORPORATION (Exact name of registrant as specified in its charter) Missouri 1-14756 43-1723446 (State or other jurisdiction of incorporation) (Commission File

Ameren Indenture Company Order, dated November 20, 2023, establishing the 5.70% Senior Notes due 2026 (including the global note)

Exhibit 4.3 AMEREN CORPORATION Company Order November 20, 2023 The Bank of New York Mellon Trust Company, N.A., as Trustee 2 North LaSalle Street, Suite 700 Chicago, Illinois 60602 Re: 5.70% Senior Notes due 2026 Ladies and Gentlemen: Application is hereby made to The Bank of New York Mellon Trust Company, N.A., a national banking association, as successor trustee (the “Trustee”), under the Indent

Global Notes.

Exhibit 4.4 REGISTERED REGISTERED THIS NOTE IS A GLOBAL NOTE REGISTERED IN THE NAME OF THE DEPOSITARY (REFERRED TO HEREIN) OR A NOMINEE THEREOF AND, UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE FOR THE INDIVIDUAL NOTES REPRESENTED HEREBY AS PROVIDED IN THE INDENTURE REFERRED TO BELOW, THIS NOTE MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE O

Underwriting Agreement, dated November 15, 2023, between Ameren and the several underwriters named therein, for whom Barclays Capital Inc., Goldman Sachs & Co. LLC, J.P. Morgan Securities LLC, Mizuho Securities USA LLC and Wells Fargo Securities, LLC are acting as representatives.

Exhibit 1 Execution Version Ameren Corporation $600,000,000 5.70% Senior Notes due 2026 Underwriting Agreement November 15, 2023 Barclays Capital Inc. 745 Seventh Avenue New York, New York 10019 Goldman Sachs & Co. LLC 200 West Street New York, New York 10282 J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179 Mizuho Securities USA LLC 1271 Avenue of the Americas New York, New Y