Item 7.01. Regulation FD Disclosure. On July 16, 2026, Pennsylvania-American Water Company (“Pennsylvania American Water”), a subsidiary of American Water Works Company, Inc. (the “Company”), issued a press release with respect to the July 16, 2026 decision of the Pennsylvania Public Utility Commission (the “PaPUC”) related to a general rate case filed by Pennsylvania American Water on November 14, 2025. A copy of this press release has been included in this Current Report on Form 8-K as Exhibit 99.1 and is incorporated by reference herein. Pennsylvania American Water is reviewing the PaPUC’s decision and expects to receive a final order from the PaPUC in due course. The information furnished in response to this Item 7.01, including Exhibit 99.1 , shall not be deemed to be “filed” for purposes Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing. Item 9.01. Financial Statements and Exhibits. (d) Exhibits. The following exhibits to this Current Report have been provided herewith as noted below: Exhibit No. Description 99.1* Press Release, dated July 16 , 2026, issued by Pennsylvania American Water. 104 Cover Page Interactive Data File (the cover page XBRL tags are included and formatted as Inline XBRL). * Furnished herewith. 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. AMERICAN WATER WORKS COMPANY, INC. Dated: July 16, 2026 By: /s/ DAVID M. BOWLER David M. Bowler Executive Vice President and Chief Financial Officer 3