Material Event (Form 8-K)

On May 18, 2026, American Water Capital Corp. ("AWCC"), a wholly owned finance subsidiary of American Water Works Company, Inc. ("American Water"), agreed to sell $500 million aggregate principal amount of its 4.625% Senior Notes due 2029 (the "Notes") pursuant to an underwriting agreement, dated May 18, 2026, by and among AWCC and American Water, and BofA Securities, Inc., RBC Capital Markets, LLC and Wells Fargo Securities, LLC, as representatives of the several underwriters named therein. The Notes have the benefit of a support agreement, dated June 22, 2000 and amended as of July 26, 2000, from American Water (the "Support Agreement").

The Notes and the obligations of American Water represented by the Support Agreement were registered under the Securities Act, pursuant to a Registration Statement on Form S-3 (File Nos. 333-277166-01 and 333-277166). At the closing of this offering, on May 20, 2026, AWCC received, after deduction of underwriting discounts and before deduction of offering expenses, net proceeds of approximately $498.0 million. AWCC intends to use the net proceeds of the offering (1) to repay a portion of AWCC's outstanding 3.625% exchangeable senior notes due 2026 upon maturity; (2) to repay a portion of the outstanding commercial paper obligations of AWCC; and (3) for general corporate purposes.

The Notes were issued pursuant to the Indenture, dated as of December 4, 2009, by and between AWCC and Computershare Trust Company, N.A., as successor to Wells Fargo Bank, National Association, as trustee, as supplemented by an officers' certificate establishing the terms of the Notes.

This Current Report on Form 8-K is being filed, in part, to report the closing of the offering of the Notes and to include, as exhibits, certain documents executed in connection with such registered public offering and sale.