SEC Form 4 · accession 0000354190-26-000178

Arthur J. Gallagher & Co. · AJG

Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗

Reporting owner

Thomas Joseph Gallagher

Officer — President

Period of report

Jul 1, 2026

Accepted (ET)

Jul 6, 2026 · 8:18 pm EDT

Rule 10b5-1 plan

box not checked

Issuer CIK

0000354190

Table I — non-derivative securities

Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock	Jul 1, 2026	M	352	$229.57	A	323,743	D
Common Stock	holding	—	—		—	62,295	I	By grantor retained annuity trust
Common Stock	holding	—	—		—	96,709	I	By Irrevocable Trust
Common Stock	holding	—	—		—	31,988	I	By wife
Common Stock^F1,F2	holding	—	—		—	119,703	I	By wife as trustee
Common Stock	holding	—	—		—	491	I	Gallagher 401(k) plan account

Table II — derivative securities

Security	Conv. / exercise price	Date	Code	Shares	A/D	Exercisable	Expires	Underlying	Underlying shares	Owned after	D/I
Notional Stock Units^F3,F4	$0.00	Jul 1, 2026	M	352	D	—	—	Common Stock	352	13,346	D
Non-qualified Stock Option^F5	$127.90	holding	—	—	—	—	Mar 16, 2028	Common Stock	32,895	32,895	D
Non-qualified Stock Option^F5	$86.17	holding	—	—	—	—	Mar 12, 2027	Common Stock	31,340	31,340	D
Non-qualified Stock Option^F6	$228.20	holding	—	—	—	—	Mar 1, 2033	Common Stock	22,219	22,219	D
Phantom Stock^F7,F8	—	holding	—	—	—	—	—	Common Stock	20,281	20,281	D
Non-qualified Stock Option^F5	$158.56	holding	—	—	—	—	Mar 15, 2029	Common Stock	15,310	15,310	D
Non-qualified Stock Option^F9	$243.54	holding	—	—	—	—	Mar 1, 2031	Common Stock	15,070	15,070	D
Non-qualified Stock Option^F10,F5	$337.74	holding	—	—	—	—	Mar 1, 2032	Common Stock	14,876	14,876	D
Non-qualified Stock Option^F11	$177.09	holding	—	—	—	—	Mar 15, 2030	Common Stock	12,744	12,744	D

Explanation of responses

F1The reporting person disclaims beneficial ownership of these shares, and this report shall not be deemed an admission that the reporting person is the beneficial owner of these shares for purposes of Section 16 or for any other purpose.
F10Closing price of Gallagher common stock on February 28, 2025.
F11One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date.
F2These shares are held in trusts, for the benefit of the reporting person's children, of which his wife is a trustee.
F3Each notional stock unit represents a right to receive one share of Gallagher common stock.
F4Portions of these notional stock units are payable to the reporting person in shares of common stock in July of 2026 and following the reporting person's separation from service.
F5One-third of this stock option becomes exerciseable on each of the 3rd, 4th, and 5th anniversaries of the grant date.
F6One-third of this stock option becomes exerciseable on each of the 3rd, 4th, and 5th anniversaries of the grant date.
F7Each share of phantom stock represents a right to receive one share of Gallagher common stock.
F8These 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.
F9One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date.

Remarks

This report discloses the distribution of notional stock units (representing compensation previously deferred by the reporting person in the Arthur J. Gallagher & Co. Supplemental Savings and Thrift Plan) in the form of Gallagher common stock. The timing of this distribution in July 2026 is in accordance with the terms of the Supplemental Savings and Thrift Plan and the reporting person's election at the time of deferral.