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post-202602030001530950false00015309502026-02-032026-02-03

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 3, 2026

Post Holdings, Inc. (Exact name of registrant as specified in its charter)

Missouri001-3530545-3355106 (State or other jurisdiction of incorporation)(Commission File Number)(IRS Employer Identification No.)

2503 S. Hanley Road St. Louis, Missouri 63144 (Address of principal executive offices) (Zip Code) Registrant’s telephone number, including area code: (314) 644-7600 Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant 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 classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value per sharePOSTNew 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 ☐ 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. ☐

Item 2.02.    Results of Operations and Financial Condition. On February 5, 2026, Post Holdings, Inc. (the “Company”) issued a press release announcing results for its first fiscal quarter ended December 31, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and incorporated herein by reference. The information contained in this Item 2.02 and Exhibit 99.1 attached hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing. Item 5.02.    Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. (d) Newly Elected Directors. On February 3, 2026, the Board of Directors (the “Board”) of the Company appointed Michelle M. Atkinson and Jeff A. Zadoks to serve as directors, effective March 15, 2026, each for a term that will expire at the Company’s annual meeting of shareholders to be held in 2027. With the addition of Ms. Atkinson and Mr. Zadoks, the Board will consist of nine members. Ms. Atkinson and Mr. Zadoks were appointed to the Board after a thorough review of each of their respective qualifications and recommendation by the Corporate Governance and Compensation Committee of the Board. Each of Ms. Atkinson and Mr. Zadoks will receive compensation as non-employee directors in accordance with the Company’s non-employee director compensation program described in the Company’s Definitive Proxy Statement filed with the Securities and Exchange Commission (the “SEC”) on December 15, 2025. The Company expects to enter into indemnification agreements with each of Ms. Atkinson and Mr. Zadoks, which (i) for Ms. Atkinson, will be an updated version of the Company’s standard form of indemnification agreement to be used for directors and is attached hereto as Exhibit 10.1 and (ii) for Mr. Zadoks, will be a form of indemnification agreement to be used for former executives of the Company who become directors and is attached hereto as Exhibit 10.2. There is no arrangement or understanding between Ms. Atkinson and any other person pursuant to which she was appointed as a director, and there are no transactions in which Ms. Atkinson has an interest requiring disclosure under Item 404(a) of Regulation S-K. The Board has determined that Ms. Atkinson is independent under the listing standards of the New York Stock Exchange and the Company’s Corporate Governance Guidelines. There is no arrangement or understanding between Mr. Zadoks and any other person pursuant to which he was appointed as a director. Mr. Zadoks served as an employee of the Company from October 2011 until his retirement in January 2026, and his compensation and related arra

post-202511180001530950false00015309502025-11-182025-11-18

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 18, 2025

Post Holdings, Inc. (Exact name of registrant as specified in its charter)

Missouri001-3530545-3355106 (State or other jurisdiction of incorporation)(Commission File Number)(IRS Employer Identification No.)

2503 S. Hanley Road St. Louis, Missouri 63144 (Address of principal executive offices) (Zip Code) Registrant’s telephone number, including area code: (314) 644-7600 Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant 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 classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value per sharePOSTNew 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 ☐ 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. ☐

Item 2.02.    Results of Operations and Financial Condition. On November 20, 2025, Post Holdings, Inc. (the “Company”) issued a press release announcing results for its fourth fiscal quarter and fiscal year ended September 30, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and incorporated herein by reference. The information contained in this Item 2.02 and Exhibit 99.1 attached hereto shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing. Item 5.02.    Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. On November 18, 2025, William P. Stiritz, Chairman of the Company’s Board of Directors (the “Board”), notified the Company of his decision to retire from the Board. Mr. Stiritz, age 91, has been Chairman of the Board since February 2012 and previously served as the Company’s Chief Executive Officer from February 2012 until November 2014 and the Company’s Executive Chairman from November 2014 until February 2016. Mr. Stiritz’s announced retirement was not due to any disagreement with the Company on any matter. Mr. Stiritz’s retirement from the Board and all committees thereof will be effective on December 16, 2025, and upon his retirement, Mr. Stiritz will become the Board’s honorary Chairman Emeritus. In connection with Mr. Stiritz’s retirement from the Board, on November 19, 2025, the Board appointed Robert V. Vitale, age 59, the Company’s President and Chief Executive Officer and current member of the Board, to also serve as Chairman of the Board, effective upon Mr. Stiritz’s retirement. Item 9.01.     Financial Statements and Exhibits. (d) Exhibits.

Exhibit No. Description

99.1Earnings Release dated November 20, 2025

104Cover Page Interactive Data File (the cover page XBRL tags are embedded within the Inline XBRL document)

2

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: November 20, 2025 Post Holdings, Inc.

(Registrant)

By: /s/ Matthew J. Mainer

Name: Matthew J. Mainer

Title: Executive Vice President, Chief Financial Officer and Treasurer

3