X0508 4 2025-03-12 0000354190 Arthur J. Gallagher & Co. AJG 0001410235 Bay Walter D. 2850 GOLF ROAD ROLLING MEADOWS IL 60008-4002 1 General Counsel 0 Common Stock (restricted) 2025-03-12 4 M 0 2250 0 D 0 D Common Stock 2025-03-12 4 M 0 2250 0 A 76422 D Common Stock 2025-03-12 4 F 0 945 325.75 D 75477 D Common Stock 367.542 I Gallagher 401(k) plan account /s/ Ryan Session, by power of attorney 2025-03-14