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

Ameren Corporation

(Missouri Corporation)

1901 Chouteau Avenue

St. Louis, Missouri 63103

(314) 621-3222

43-1723446

1-3672

Ameren Illinois Company

(Illinois Corporation)

10 Richard Mark Way

Collinsville, Illinois 62234

(618) 343-8150

37-0211380

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrants under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common Stock, $0.01 par value per share		AEE		New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

	Emerging growth company
Ameren Corporation	¨
Ameren Illinois Company	¨

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

Ameren Corporation	¨
Ameren Illinois Company	¨

ITEM 8.01

Other Events.

On March 3, 2025, Ameren Illinois Company (“Ameren Illinois”), a subsidiary of Ameren Corporation, sold $350 million principal amount of its 5.625% First Mortgage Bonds due 2055 (the “Bonds”). The Bonds were offered pursuant to a Registration Statement on Form S-3 (File No. 333-274977-01), which became effective on October 13, 2023, and a Prospectus Supplement dated February 24, 2025, to a Prospectus dated October 13, 2023. Ameren Illinois received net offering proceeds of approximately $346.9 million, before expenses, upon closing of the transaction.

This Current Report on Form 8-K is being filed to report as exhibits certain documents in connection with the offering of the Bonds.

ITEM 9.01

Financial Statements and Exhibits.

(d)

Exhibits

Exhibit Number		Title

1.1		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.

4.1*		General Mortgage Indenture and Deed of Trust, dated as of November 1, 1992, from Ameren Illinois to The Bank of New York Mellon Trust Company, N.A., as successor trustee (1992 Form 10-K, Exhibit 4(cc), File No. 1-3004).

4.2		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.

5.1		Opinion of Stephen C. Lee, Esq., Vice President and Deputy General Counsel of Ameren Illinois, regarding the legality of the Bonds (including consent).

5.2		Opinion of Morgan, Lewis & Bockius LLP regarding the legality of the Bonds (including consent).

104		Cover Page Interactive Data File (formatted as Inline XBRL).

* Incorporated by reference as indicated.

This combined Form 8-K is being filed separately by Ameren Corporation and Ameren Illinois Company (each a “registrant”). Information contained herein relating to any individual registrant has been filed by such registrant on its own behalf. No registrant makes any representation as to information relating to any other registrant.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, each registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized. The signature for each undersigned company shall be deemed to relate only to matters having reference to such company or its subsidiaries.

	AMEREN CORPORATION
	(Registrant)

	By:	/s/ Michael L. Moehn
	Name:	Michael L. Moehn
	Title:	Senior Executive Vice President and Chief Financial Officer

	AMEREN ILLINOIS COMPANY
	(Registrant)

	By:	/s/ Leonard P. Singh
	Name:	Leonard P. Singh
	Title:	Chairman and President

Date: March 3, 2025

Co-Registrant CIK	0000100826
Co-Registrant Amendment Flag	false
Co-Registrant Form Type	8-K
Co-Registrant DocumentperiodEndDate	2025-03-03
Co-Registrant Written Commuunications	false
Co-Registrant Solicitating Materials	false
Co-Registrant PreCommencement Tender Offer	false
Co-Registrant PreCommencement Tender Offer	false
Co-Registrant Entity PreCommencement Issuer Tender Offer	false

Ameren Illinois Co 8-K