X0508 4 2026-03-03 0 0001035201 CALIFORNIA WATER SERVICE GROUP CWT 0002058905 HAMNER KRISTAN A 1720 NORTH FIRST STREET SAN JOSE CA 95112 0 1 0 0 VP, Chief Human Resource Offcr 0 Common Stock 2026-03-03 4 A 0 1650 0.0 A 3133.457 D Common Stock 2026-03-04 4 F 0 190 46.99 D 2943.457 D Restricted stock granted on 3/3/2026 pursuant to the California Water Service Group equity incentive plan in a transaction exempt under Rule 16-b-3 vests with one-third on March 3, 2027, and with the remaining 2/3 vesting quarterly over the succeeding 24 months. Includes shares acquired through the Employee Stock Purchase Program. 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 4,2025 By: /s/ Michelle R. Mortensen For: Kristan Hamner 2026-03-05