AEEAmeren

On August 6, 2026, Theresa A. Shaw, Senior Vice President, Chief Accounting and Transformation Officer of Ameren, adopted a Rule 10b5-1 trading arrangement that provides for the sale of up to an aggregate of approximately 7,640 shares, consisting of: • up to 500 shares on a quarterly basis between November 2026 and November 2027, subject to certain price limitations set forth in the trading arrangement; and • shares acquired upon vesting of certain equity awards, consisting of (i) 100% of shares delivered from the 2024 restricted stock units award scheduled to vest on March 1, 2027 (approximately 1,692 shares before applicable tax withholding), and (ii) 5% of shares delivered from the 2024 performance condition performance share units and 2024 market condition performance share units awards scheduled to vest on March 1, 2027 (approximately 564 shares and 3,384 shares, respectively, before applicable performance adjustments and tax withholding). Ms. Shaw’s 10b5-1 trading arrangement will terminate on the earlier of: (i) November 16, 2027; (ii) execution of all trades or expiration of all orders relating to such trades under the Rule 10b5-1 trading arrangement; or (iii) such date as the Rule 10b5-1 trading arrangement is otherwise terminated according to its terms.

On February 24, 2026, Mark C. Lindgren, Executive Vice President, Communications, and Chief Human Resources Officer of Ameren Services Company, adopted a Rule 10b5‑1 trading arrangement that provides for the sale of 50% of any net shares of Ameren common stock received, after tax withholding, in connection with certain previously awarded performance share units and restricted stock units that will vest upon payment in March 2027 and March 2028. The estimated maximum number of shares to be sold pursuant to the Rule 10b5-1 trading arrangement is 5,272 shares. The actual number of shares sold pursuant to the Rule 10b5-1 trading arrangement will depend on the actual number of shares earned pursuant to the awards, which is generally dependent on the Company's achievement of certain performance measures, the actual dividends paid by the Company during the applicable vesting periods, and Mr. Lindgren's continued employment during the applicable vesting periods. Mr. Lindgren’s Rule 10b5‑1 trading arrangement will terminate on the earlier of: (i) March 17, 2028; (ii) execution of all trades or expiration of all orders relating to such trades under the Rule 10b5‑1 trading arrangement; or (iii) such date as the Rule 10b5‑1 trading arrangement is otherwise terminated according to its terms.

On February 24, 2026, Michael L. Moehn, Group President of Ameren Utilities and Interim Chairman and President of Ameren Missouri, adopted a Rule 10b5‑1 trading arrangement that provides for the sale of an aggregate of up to 26,000 shares of Ameren common stock, to be sold in four equal quarterly installments, beginning in August 2026 and continuing through May 2027, subject to certain price limitations set forth in the trading arrangement. Mr. Moehn’s Rule 10b5‑1 trading arrangement will terminate on the earlier of: (i) July 30, 2027; (ii) execution of all trades or expiration of all orders relating to such trades under the Rule 10b5‑1 trading arrangement; or (iii) such date as the Rule 10b5‑1 trading arrangement is otherwise terminated according to its terms.

On August 13, 2025, Theresa A. Shaw, Senior Vice President, Finance and Chief Accounting Officer of Ameren, adopted a Rule 10b5-1 trading arrangement that provides for the sale of an aggregate of up to 1,300 shares to be sold in four equal quarterly installments between November 2025 and November 2026, subject to certain price limitations set forth in the trading arrangement. Ms. Shaw’s 10b5-1 trading arrangement will terminate on the earlier of: (i) November 13, 2026; (ii) execution of all trades or expiration of all orders relating to such trades under the Rule 10b5-1 trading arrangement; or (iii) such date as the Rule 10b5-1 trading arrangement is otherwise terminated according to its terms.

On March 14, 2025, Michael L. Moehn, Senior Executive Vice President and Chief Financial Officer of Ameren, adopted a Rule 10b5-1 trading arrangement. Mr. Moehn's Rule 10b5-1 trading arrangement provides for the sale of an aggregate 26,000 shares to be sold in four equal quarterly installments between August 2025 and July 2026. Mr. Moehn’s Rule 10b5-1 trading arrangement will terminate on the earlier of: (i) July 31, 2026; (ii) execution of all trades or expiration of all orders relating to such trades under the Rule 10b5-1 trading arrangement; or (iii) such date as the Rule 10b5-1 trading arrangement is otherwise terminated according to its terms.

On March 11, 2025, Martin J. Lyons, Jr., Chairman, President, and Chief Executive Officer of Ameren, adopted a Rule 10b5-1 trading arrangement. Mr. Lyons’ Rule 10b5-1 trading arrangement provides for the sale of 75% of any net shares of Ameren common stock received, after tax withholding, in connection with certain previously awarded restricted stock units and performance share units that will vest upon payment in March 2026 and March 2027. The estimated maximum number of shares to be sold pursuant to the Rule 10b5-1 trading arrangement is 62,686 shares. The actual number of shares sold pursuant to the Rule 10b5-1 trading arrangement will depend on the actual number of shares earned pursuant to the awards, which is generally dependent on the Company's achievement of certain performance measures, the actual dividends paid by the Company during the applicable vesting periods, and Mr. Lyons’ continued employment and individual performance during the applicable vesting periods. Mr. Lyons’ Rule 10b5-1 trading arrangement will terminate on the earlier of: (i) March 31, 2027; (ii) execution of all trades or expiration of all orders relating to such trades under the Rule 10b5-1 trading arrangement; or (iii) such date as the Rule 10b5-1 trading arrangement is otherwise terminated according to its terms.

On June 6, 2024, Mark C. Lindgren, Executive Vice President, Corporate Communications, and Chief Human Resources Officer of Ameren Services Company, adopted a Rule 10b5-1 trading arrangement. Mr. Lindgren's Rule 10b5-1 trading arrangement provides for the sale of 50% of any net shares of Ameren common stock received, after tax withholding, in connection with certain previously awarded restricted stock units and performance share units that will vest upon payment in March 2025 and March 2026. The estimated maximum number of shares to be sold pursuant to the Rule 10b5-1 trading arrangement is 3,841 shares. The actual number of shares sold pursuant to the Rule 10b5-1 trading arrangement will depend on the actual number of shares earned pursuant to the awards, which is generally dependent on the Company's achievement of certain performance measures, the actual dividends paid by the Company during the applicable vesting periods, and Mr. Lindgren's continued employment and individual performance during the applicable vesting periods. Mr. Lindgren's Rule 10b5-1 trading arrangement will terminate on the earlier of: (i) March 31, 2026; (ii) execution of all trades or expiration of all orders relating to such trades under the Rule 10b5-1 trading arrangement; or (iii) such date as the Rule 10b5-1 trading arrangement is otherwise terminated according to its terms.

On May 22, 2024, Shawn E. Schukar, Chairman and President of ATXI, adopted a Rule 10b5-1 trading arrangement. Mr. Schukar's Rule 10b5-1 trading arrangement provides for the sale of 100% of any net shares of Ameren common stock received, after tax withholding, in connection with certain previously awarded restricted stock units and performance share units that will vest upon payment in March 2025 and March 2026. The estimated maximum number of shares to be sold pursuant to the Rule 10b5-1 trading arrangement is 10,170 shares. The actual number of shares sold pursuant to the Rule 10b5-1 trading arrangement will depend on the actual number of shares earned pursuant to the awards, which is generally dependent on the Company's achievement of certain performance measures, the actual dividends paid by the Company during the applicable vesting periods, and Mr. Schukar's continued employment and individual performance during the applicable vesting periods. Mr. Schukar's Rule 10b5-1 trading arrangement will terminate on the earlier of: (i) March 31, 2026; (ii) execution of all trades or expiration of all orders relating to such trades under the Rule 10b5-1 trading arrangement; or (iii) such date as the Rule 10b5-1 trading arrangement is otherwise terminated according to its terms.