X0306 4 2019-11-15 0000354190 ARTHUR J. GALLAGHER & CO. AJG 0001186006 GALLAGHER J PATRICK JR 2850 GOLF ROAD ROLLING MEADOWS IL 60008-4002 1 1 President & CEO Common Stock 2019-11-15 4 F 0 599 91.95 D 77759.2368 D Common Stock 2019-11-15 4 M 0 599 0 A 78358.2368 D Common Stock 205965 I By Corporation Common Stock 66703 I By Irrevocable Trust Common Stock 246538 I By Spouse Common Stock 218697 I By Trust Phantom Stock 2019-11-15 4 M 0 599 0 D Common Stock 599 119513 D Shares held in revocable trust of which my spouse is sole Trustee and as to which I disclaim beneficial ownership. Held in trust for benefit of children. Each share of phantom stock represents a right to receive one share of Gallagher common stock. These shares represent awards under the Age 62 Plan, a nonqualified deferred compensation plan of the Company, which have been deemed invested in Company common stock at the election of the reporting person. Participants vest in these awards when they attain age 62, or after a one-year period for participants who have attained age 61. This report is being filed to reflect an accelerated distribution under the Age 62 Plan to cover applicable taxes in connection with a vesting. /s/ April Hanes-Dowd, by power of attorney 2019-11-15