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mwa-202602040001350593FALSE00013505932026-02-042026-02-04

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 4, 2026

MUELLER WATER PRODUCTS, INC.

(Exact Name of Registrant as Specified in Its Charter) Delaware001-32892 20-3547095

(State or Other Jurisdiction of Incorporation or Organization)(Commission File Number) (I.R.S. Employer Identification No.)

1200 Abernathy Road N.E. Suite 1200 Atlanta, Georgia 30328 (Address of Principal Executive Offices) (770) 206-4200 (Registrant’s telephone number, including area code) Not Applicable. (Former name or former address, if changed since last report)

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 communication 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, par value $0.01 per shareMWANew 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 4, 2026, Mueller Water Products, Inc. (the “Company”) announced its results of operations for the quarter ended December 31, 2025. A copy of the press release is attached as Exhibit 99.1. The information provided pursuant to this Item 2.02, including Exhibit 99.1 in Item 9.01, is “furnished” and shall not be deemed to be “filed” with the Securities and Exchange Commission or incorporated by reference in any filing under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or the Securities Act of 1933, as amended (the “Securities Act”), except as shall be expressly set forth by specific reference in any such filings.

Item 9.01.    Financial Statements and Exhibits. (d) Exhibits. 99.1 Press Release regarding Results of Operations for the Quarter Ended December 31, 2025, dated February 4, 2026

104The cover page of this Current Report on Form 8-K, formatted in Inline XBRL

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, Mueller Water Products, Inc. has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

Dated:  February 4, 2026MUELLER WATER PRODUCTS, INC.

By:/s/ Melissa Rasmussen Melissa Rasmussen Senior Vice President and Chief Financial Officer

mwa-202511060001350593FALSE00013505932025-11-062025-11-06

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, 2025

MUELLER WATER PRODUCTS, INC.

(Exact Name of Registrant as Specified in Its Charter) Delaware001-32892 20-3547095

(State or Other Jurisdiction of Incorporation or Organization)(Commission File Number) (I.R.S. Employer Identification No.)

1200 Abernathy Road N.E. Suite 1200 Atlanta, Georgia 30328 (Address of Principal Executive Offices) (770) 206-4200 (Registrant’s telephone number, including area code) Not Applicable. (Former name or former address, if changed since last report)

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 communication 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, par value $0.01 per shareMWANew 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 6, 2025, Mueller Water Products, Inc. (the “Company”) announced its results of operations for the quarter and fiscal year ended September 30, 2025. A copy of the press release is attached as Exhibit 99.1. The information provided pursuant to this Item 2.02, including Exhibit 99.1 in Item 9.01, is “furnished” and shall not be deemed to be “filed” with the Securities and Exchange Commission or incorporated by reference in any filing under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or the Securities Act of 1933, as amended (the “Securities Act”), except as shall be expressly set forth by specific reference in any such filings.

Item 9.01.    Financial Statements and Exhibits. (d) Exhibits. 99.1 Press Release regarding Results of Operations for the Quarter and Fiscal Year Ended September 30, 2025, dated November 6, 2025

104The cover page of this Current Report on Form 8-K, formatted in Inline XBRL

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, Mueller Water Products, Inc. has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

Dated:  November 6, 2025MUELLER WATER PRODUCTS, INC.

By:/s/ Melissa Rasmussen Melissa Rasmussen Senior Vice President and Chief Financial Officer