American Water Works Company, Inc. and its Designated Subsidiaries2017 Nonqualified Employee Stock Purchase Plan B.Name of issuer of the securities held pursuant to the plan and the address of its principal executive office: Report of Independent Registered Public Accounting Firm Financial StatementsStatements of Financial Condition as of December 31, 2025 and 2024Statements of Changes in Net Income and Plan Equity for the years ended December 31, 2025, 2024 and 2023 Report of Independent Registered Public Accounting Firm To the Benefit Administration Committee ofAmerican Water Works Company, Inc. Opinion on the Financial Statements We have audited the accompanying statements of financial condition of American Water Works Company, Inc. and itsDesignated Subsidiaries 2017 Nonqualified Employee Stock Purchase Plan (the “Plan”) as of December31, 2025 and 2024, and therelated statements of changes in net income and plan equity for the years ended December31, 2025, 2024, and 2023, and the relatednotes (collectively referred to as the financial statements). In our opinion, the financial statements present fairly, in all material Basis for Opinion These financial statements are the responsibility of the plan's management. Our responsibility is to express an opinion onthese financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and performthe audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whetherdue to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis,evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting We have served as the Plan’s auditor since 2017. /s/ Kreischer MillerHorsham, PennsylvaniaMarch 20, 2026 AMERICAN WATER WORKS COMPANY, INC. AND ITS DESIGNATED SUBSIDIARIES2017 NONQUALIFIED EMPLOYEE STOCK PURCHASE PLAN Note 1: Description of Plan General The following description of the American Water Works Company, Inc. and its Designated Subsidiaries 2017 NonqualifiedEmployee Stock Purchase Plan (the “Plan”) provides only general information. Participants should refer to the plan document for amore complete description of the Plan’s provisions. The Plan was initially adopted by the Board of Directors (the “Board”) ofAmerican Water Works Company, Inc. (the “Company”) on February 15, 2017, was approved as such by the shareholders of theCompany on May 12, 2017, and was initially effective as of August 5, 2017. The Board may, at any time and from time to time, amendthe Plan, except that any amendment that is required to be approved by the shareholders shall be submitted to the shareholders of the The purpose of the Plan is to provide eligible employees of the Company and its designated subsidiaries an opportunity topurchase an equity interest in the Company through the purchase of shares of the Company’s common stock. Participants maycontribute portions of their compensation during a three-month purchase period and purchase common stock at the end thereof.Participation in the Plan entitles each participant to purchase the Company’s common stock at 85% of the fair market value of such Eligibility Full or part time employees of the Company and its designated subsidiaries receiving a paycheck or direct deposit are eligible toparticipate in the Plan, except for (i) temporary or leased employees, (ii) an employee of a non-U.S. subsidiary of the Company, (iii)any person who is determined by the Board to be an officer of American Water, as defined under Section 16 of the Securities ExchangeAct of 1934, as amended, and rules promulgated thereunder, and (iv) an employee who owns stock possessing 5% or more of the totalcombined voting power or value of all classes of the Company’s stock. Each eligible employee as defined in the Plan may enroll as Participant Contributions A Plan participant may contribute (i) from 1% to 10%, in 1% increments, or (ii) a fixed amount from $5 to $2,500 per payperiod of their pre-tax eligible compensation, in each case subject to the maximum deduction amount of $25,000 per Plan year.Participants may not increase or decrease their withholding percentage or their fixed contribution amount during a purchase period.The Company holds contributions of participants during the purchase period, and then issues shares purchased by the participantsbased on the amount of the contributions received from them and at a purchase price of 85% of the fair market value of the Company’s Withdrawals A participant may cancel or suspend Plan enrollment at any time and either withdraw Pla