Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * GALLAGHER J PATRICK JR 2. Issuer Name and Ticker or Trading Symbol Arthur J. Gallagher & Co. [AJG] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) CEO (Last) (First) (Middle) 2850 GOLF ROAD 3. Date of Earliest Transaction (Month/Day/Year) 03/02/2026 (Street) ROLLING MEADOWS, IL 60008-4002 4. If Amendment, Date Original Filed (Month/Day/Year) 6. Individual or Joint/Group Filing (Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 03/02/2026 M 44,050 A $79.59 123,904.9335 D Common Stock 03/02/2026 S(1) 27,450 D $230.312(2) 96,454.9335 D Common Stock 03/03/2026 G 1,350 D $ 0 95,104.9335 D Common Stock 03/03/2026 G 1,350 D $ 0 270,175 I By Spouse(3) Common Stock 03/03/2026 G 600 A $ 0 219,955 I By Trust(4) Common Stock 5,328 I By Spouse's Trust(5) Common Stock 255,965 I By Corporation Common Stock 66,703 I By Irrevocable Trust Common Stock 418.702 I Gallagher 401(k) plan account

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Underlying Securities (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Notional Stock Units	$ 0 (6)	03/03/2026		I		91,769.428(7)		(8)	(8)	Common Stock	91,769.428	$225.23	153,072.954	D
Non-qualified Stock Option	$79.59	03/02/2026		M			44,050	(9)	03/14/2026	Common Stock	44,050	$ 0	0	D
Phantom Stock	(10)							(11)	(11)	Common Stock	136,060.984		136,060.984	D
Non-qualified Stock Option	$86.17							(9)	03/12/2027	Common Stock	68,550		68,550	D
Non-qualified Stock Option	$127.9							(9)	03/16/2028	Common Stock	76,975		76,975	D
Non-qualified Stock Option	$158.56							(9)	03/15/2029	Common Stock	35,825		35,825	D
Non-qualified Stock Option	$177.09							(12)	03/15/2030	Common Stock	30,029		30,029	D
Non-qualified Stock Option	$243.54							(13)	03/01/2031	Common Stock	27,210		27,210	D
Non-qualified Stock Option	$337.74							(9)	03/01/2032	Common Stock	22,727		22,727	D
Non-qualified Stock Option	$228.2							(14)	03/01/2033	Common Stock	48,449		48,449	D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
GALLAGHER J PATRICK JR 2850 GOLF ROAD ROLLING MEADOWS, IL 60008-4002	X		CEO

Signatures

/s/ Monica Norzagaray, by power of attorney		03/04/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Covers tax obligations and the exercise price relating to the exercise of expiring stock options.
(2)	The price reported is an average weighted price. The shares were sold in multiple transactions at prices ranging from $230.210 to $230.780. The reporting person will provide to the Securities and Exchange Commission staff, the issuer, or any security holder of the issuer, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
(3)	Shares held in revocable trust of which my spouse is sole Trustee and as to which I disclaim beneficial ownership.
(4)	Held in trust for benefit of children.
(5)	Shares held in trust for the benefit of my children of which I am sole Trustee.
(6)	Each notional stock unit represents a right to receive one share of Gallagher common stock.
(7)	The reporting person moved $20,669,228.36 in assets that he holds in the company's Supplemental Savings and Thrift Plan, a nonqualified deferred compensation plan, into the investment option representing Gallagher common stock, which is a discretionary transaction by the reporting person.
(8)	The notional stock units become payable following the reporting person's separation from service with Gallagher.
(9)	One-third of this stock option becomes exerciseable on each of the 3rd, 4th, and 5th anniversaries of the grant date.
(10)	Each share of phantom stock represents a right to receive one share of Gallagher common stock.
(11)	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.
(12)	One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date.
(13)	One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date.
(14)	One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date.
Remarks: This report discloses several transactions by the reporting person, including an exercise of expiring stock options, gifts and a discretionary election to move $20,669,228.36 in assets that he holds in the company's Supplemental Savings and Thrift Plan, a nonqualified deferred compensation plan, into the investment option representing Gallagher common stock.

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