X0609 4 2026-09-08 0000354190 Arthur J. Gallagher & Co. AJG 0001929606 Gallagher Patrick Murphy false 2850 GOLF ROAD ROLLING MEADOWS IL 60008 1 Chief Operating Officer 0 Common Stock 2026-09-08 4 G 0 49988 0 A 148093.25 I By Trust Common Stock 11264 I By Spouse as Trustee Common Stock 14169.6426 D Common Stock 491.136 I Gallagher 401(k) plan account Common Stock 53262 I By Spouse's Trust Common Stock 21032 I By Trust Common Stock 55109 I By Irrevocable Trust Non-qualified Stock Option 228.20 2033-03-01 Common Stock 17775 17775 D Phantom Stock Common Stock 17731.211 17731.211 D Non-qualified Stock Option 337.74 2032-03-01 Common Stock 11901 11901 D Non-qualified Stock Option 243.54 2031-03-01 Common Stock 11386 11386 D Non-qualified Stock Option 127.90 2028-03-16 Common Stock 7255 7255 D Non-qualified Stock Option 86.17 2027-03-12 Common Stock 6270 6270 D Non-qualified Stock Option 177.09 2030-03-15 Common Stock 6160 6160 D Non-qualified Stock Option 158.56 2029-03-15 Common Stock 5510 5510 D Phantom Stock Common Stock 3804.562 3804.562 D Notional Stock Units Common Stock 2351.803 2351.803 D This transaction represents a gift from the reporting person's father to an irrevocable trust of which the reporting person and his siblings are beneficiaries, and the reporting person is the acting trustee. The reporting person disclaims beneficial ownership of the shares held by the trust except to the extent of his pecuniary interest therein. Shares held in trust for the benefit of the reporting person and immediate family members, of which he and his immediate family members, as applicable, is a trustee. Shares held in trusts, for the benefit of the reporting person's children, of which his wife is sole trustee. Shares held in a revocable trust and an irrevocable trust of which the reporting person's spouse is sole Trustee and as to which he disclaims beneficial ownership Shares held in trust for the benefit of the reporting person's children, of which he is a trustee. One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date. 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. Closing price of Gallagher common stock on February 28, 2025. One-third of this stock option becomes exerciseable on each of the 3rd, 4th, and 5th anniversaries of the grant date. One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date. Grant date of 3/16/2021. Grant date of 3/12/2020. One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date. Grant date of 3/15/2022. These shares represent awards under the Deferred Cash Participation Plan, a nonqualified deferred compensation plan of the Company, which have been deemed invested in Company common stock at the election of the participant. These awards are payable in a lump sum on the six-month anniversary of the reporting person's separation from service. Each notional stock unit represents a right to receive one share of Gallagher common stock. The notional stock units become payable following the reporting person's separation from service with Gallagher. The notional stock units become payable following the reporting person's separation from service with Gallagher. /s/ Monica Norzagaray, by power of attorney 2026-09-10