AWK · American Water Works Company, Inc.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

Includes 239 shares acquired pursuant to the automatic reinvestment in shares of Company common stock of cash dividends paid on Company common stock to the reporting person, received since the reporting person's last Form 4 report, which acquisition is exempt from Section 16 of the Securities Exchange Act of 1934, as amended, pursuant to Rule 16a-11 thereunder.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

Represents shares underlying an award of restricted stock units (RSUs) granted on February 17, 2026, under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. These awards will vest in three approximately equal increments on January 31, 2027, 2028 and 2029, subject to continued employment on each vesting date and applicable continued vesting provisions in the event of retirement. RSUs are settled solely by the delivery of one share of common stock per RSU (and may not be settled in cash).

Represents shares underlying an award of restricted stock units (RSUs) granted on February 17, 2026, under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. This award will vest in three approximately equal increments on January 31, 2027, 2028 and 2029, subject to continued employment on each vesting date and applicable continued vesting provisions in the event of retirement. RSUs are settled solely by the delivery of one share of common stock per RSU (and may not be settled in cash).

Represents shares underlying an award of restricted stock units (RSUs) granted on February 17, 2026, under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. These awards will vest in three approximately equal increments on January 31, 2027, 2028 and 2029, subject to continued employment on each vesting date and applicable continued vesting provisions in the event of retirement. RSUs are settled solely by the delivery of one share of common stock per RSU (and may not be settled in cash).

Represents shares vested pursuant to one or more awards of performance stock units (PSUs) granted in February 2023 under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. These awards vested on February 17, 2026. PSUs are settled solely by the delivery of one share of common stock per PSU (and may not be settled in cash).

Represents shares underlying an award of restricted stock units (RSUs) granted on February 17, 2026, under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. These awards will vest in three approximately equal increments on January 31, 2027, 2028 and 2029, subject to continued employment on each vesting date and applicable continued vesting provisions in the event of retirement. RSUs are settled solely by the delivery of one share of common stock per RSU (and may not be settled in cash).

Represents shares vested pursuant to one or more awards of performance stock units (PSUs) granted in February 2023 under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. These awards vested on February 17, 2026. PSUs are settled solely by the delivery of one share of common stock per PSU (and may not be settled in cash).

Represents shares underlying an award of restricted stock units (RSUs) granted on February 17, 2026, under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. These awards will vest in three approximately equal increments on January 31, 2027, 2028 and 2029, subject to continued employment on each vesting date and applicable continued vesting provisions in the event of retirement. RSUs are settled solely by the delivery of one share of common stock per RSU (and may not be settled in cash).

Represents shares vested pursuant to one or more awards of performance stock units (PSUs) granted in February 2023 under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. These awards vested on February 17, 2026. PSUs are settled solely by the delivery of one share of common stock per PSU (and may not be settled in cash).

Represents shares vested pursuant to one or more awards of performance stock units (PSUs) granted in February 2023 under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. These awards vested on February 17, 2026. PSUs are settled solely by the delivery of one share of common stock per PSU (and may not be settled in cash).

Represents shares vested pursuant to one or more awards of performance stock units (PSUs) granted in February 2023 under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. These awards vested on February 17, 2026. PSUs are settled solely by the delivery of one share of common stock per PSU (and may not be settled in cash).

Represents shares vested pursuant to one or more awards of performance stock units (PSUs) granted in February 2023 under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. These awards vested on February 17, 2026. PSUs are settled solely by the delivery of one share of common stock per PSU (and may not be settled in cash).

Represents shares underlying an award of restricted stock units (RSUs) granted on February 17, 2026, under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. This award will vest in three approximately equal increments on January 31, 2027, 2028 and 2029, subject to continued employment on each vesting date and applicable continued vesting provisions in the event of retirement. RSUs are settled solely by the delivery of one share of common stock per RSU (and may not be settled in cash).

Represents shares underlying an award of restricted stock units (RSUs) granted on February 17, 2026, under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. These awards will vest in three approximately equal increments on January 31, 2027, 2028 and 2029, subject to continued employment on each vesting date and applicable continued vesting provisions in the event of retirement. RSUs are settled solely by the delivery of one share of common stock per RSU (and may not be settled in cash).

Includes approximately 346 shares acquired pursuant to the automatic reinvestment in shares of common stock of American Water Works Company, Inc. (the "Company") of cash dividends paid on Company common stock to the reporting person, received since the reporting person's last Form 4 report, which acquisitions are exempt from Section 16 of the Securities Exchange Act of 1934, as amended, pursuant to Rule 16a-11 thereunder.

Includes approximately 80 shares acquired pursuant to the automatic reinvestment in shares of common stock of American Water Works Company, Inc. (the "Company") of cash dividends paid on Company common stock to the reporting person, received since the reporting person's last Form 4 report, which acquisitions are exempt from Section 16 of the Securities Exchange Act of 1934, as amended, pursuant to Rule 16a-11 thereunder.

Includes 560 shares acquired pursuant to the automatic reinvestment in shares of common stock of American Water Works Company, Inc. (the "Company") of cash dividends paid on Company common stock to the reporting person, received since the reporting person's last Form 4 report, which acquisitions are exempt from Section 16 of the Securities Exchange Act of 1934, as amended, pursuant to Rule 16a-11 thereunder.

Includes approximately 162 shares acquired pursuant to the automatic reinvestment in shares of common stock of American Water Works Company, Inc. (the "Company") of cash dividends paid on Company common stock to the reporting person, received since the reporting person's last Form 4 report, which acquisitions are exempt from Section 16 of the Securities Exchange Act of 1934, as amended, pursuant to Rule 16a-11 thereunder.

Represents shares underlying an award of restricted stock units (RSUs) granted effective October 1, 2025, under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. These awards will vest in three approximately equal increments on January 31, 2026, 2027 and 2028, subject to continued employment on each vesting date. RSUs are settled solely by the delivery of one share of common stock per RSU (and may not be settled in cash).

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

This form is being filed to timely correct the Form 4 filed on June 10, 2025 on behalf of the reporting person, which originally reported this transaction as 1,160 shares.

The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $143.13 to $143.33, inclusive. The reporting person undertakes to provide to any security holder of American Water Works Company, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth above.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

Includes 178 shares acquired pursuant to the automatic reinvestment in shares of common stock of American Water Works Company, Inc. (the "Company") of cash dividends paid on Company common stock to the reporting person, received since the reporting person's last Form 4 report, which acquisitions are exempt from Section 16 of the Securities Exchange Act of 1934, as amended, pursuant to Rule 16a-11 thereunder.

Represents shares underlying an award of restricted stock units (RSUs) granted effective May 14, 2025, under the American Water Works Company, Inc. 2017 Omnibus Equity Compensation Plan. This award will vest in three approximately equal increments on January 31, 2026, 2027 and 2028, subject to continued employment on each vesting date and applicable continued vesting provisions in the event of retirement under specified circumstances. RSUs are settled solely by the delivery of one share of common stock per RSU (and may not be settled in cash).

Includes an aggregate of 93 shares acquired pursuant to the automatic reinvestment in shares of common stock of American Water Works Company, Inc. (the "Company") of cash dividends paid on Company common stock to the reporting person, including 26 of such shares that were purchased since the reporting person's last Form 4 and 67 of such shares that were inadvertently omitted from certain of the reporting person's prior Form 4s, which acquisitions are exempt from Section 16 of the Securities Exchange Act of 1934, as amended, pursuant to Rule 16a-11 thereunder.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.

The shares indicated constitute units that settle solely in the common stock of American Water Works Company, Inc. (the "Company") on a one-share-per-unit basis. The stock units vested on the date of grant and will be converted immediately into shares of Company common stock.