X0508 4 2025-12-05 0 0001035201 CALIFORNIA WATER SERVICE GROUP CWT 0001629473 Mortensen Michelle R 1720 NORTH FIRST STREET SAN JOSE CA 95112 0 1 0 0 VP Corp Sect & Chief of Staff 0 Common Stock 2025-12-05 4 F 0 73 44.88 D 12492.8 D Common Stock 2025-12-07 4 F 0 57 44.88 D 12435.8 D Represents the number of shares withheld and surrendered to the issuer to satisfy the tax withholding obligations that arose in connection with the vesting of Restricted Stock (RSA) Award granted on June 5, 2024. Represents the number of shares withheld and surrendered to the issuer to satisfy the tax withholding obligations that arose in connection with the vesting of Restricted Stock (RSA) Award granted on March 7, 2023. By: /s/ Michelle R. Mortensen For: Michelle R. Mortensen 2025-12-09