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 * HOWELL DOUGLAS K 2. Issuer Name and Ticker or Trading Symbol Arthur J. Gallagher & Co. [AJG] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) VP & Chief Financial Officer (Last) (First) (Middle) 2850 GOLF ROAD 3. Date of Earliest Transaction (Month/Day/Year) 12/22/2025 (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 12/22/2025 S(1) 5,000 D $258.0485(2) 95,776.7558 D Common Stock 12/22/2025 G 196 D $ 0 95,580.7558(3) D Common Stock 3,165 I By Spouse(4) Common Stock 418.691 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 (5)							(6)	(6)	Common Stock	208,342.081		208,342.081	D
Notional Stock Units	$ 0 (5)							(7)	(7)	Common Stock	177,994.9726		177,994.9726	D
Non-qualified Stock Option	$127.9							(8)	03/16/2028	Common Stock	31,265		31,265	D
Non-qualified Stock Option	$86.17							(8)	03/12/2027	Common Stock	17,130		17,130	D
Non-qualified Stock Option	$158.56							(8)	03/15/2029	Common Stock	14,545		14,545	D
Non-qualified Stock Option	$79.59							(8)	03/14/2026	Common Stock	14,100		14,100	D
Non-qualified Stock Option	$337.74(9)							(8)	03/01/2032	Common Stock	13,884		13,884	D
Non-qualified Stock Option	$243.54							(10)	03/01/2031	Common Stock	12,726		12,726	D
Non-qualified Stock Option	$177.09							(11)	03/15/2030	Common Stock	12,107		12,107	D
Phantom Stock	(12)							(13)	(13)	Common Stock	4,257.047		4,257.047	D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
HOWELL DOUGLAS K 2850 GOLF ROAD ROLLING MEADOWS, IL 60008-4002			VP & Chief Financial Officer

Signatures

/s/ Monica Norzagaray, by power of attorney		12/29/2025
**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)	This report discloses a sale of shares to cover tax obligations relating to the distribution of 35,739 deferred shares under the company's Supplemental Savings and Thrift Plan (reported on August 4, 2025). In lieu of withholding for taxes, the reporting person was required to receive the full distribution of shares and subsequently sell a portion of such shares to cover his tax obligation.
(2)	The price reported is an average weighted price. The shares were sold in multiple transactions on 12/22/2025 at prices ranging from $257.730 to $258.250. 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 ranges set forth in the footnotes to this Form 4.
(3)	In the past, Common Stock and Common Stock (Restricted) were reported as two separate line items. In the future, they will be reported as a combined total as is stated on this Form.
(4)	The reporting person has no voting or invesment power over these shares and disclaims beneficial ownership.
(5)	Each notional stock unit represents a right to receive one share of Gallagher common stock.
(6)	The notional stock units become payable following the reporting person's separation from service with Gallagher.
(7)	Portions of these notional stock units are payable to the reporting person in shares of common stock in July of 2026, 2028 and 2029 and following the reporting person's separation from service.
(8)	One-third of this stock option becomes exerciseable on each of the 3rd, 4th, and 5th anniversaries of the grant date.
(9)	Closing price of Gallagher common stock on February 28, 2025.
(10)	One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date.
(11)	One-third of this stock option becomes exerciseable on each of the 3rd, 4th, and 5th anniversaries of the grant date.
(12)	Each share of phantom stock represents a right to receive one share of Gallagher common stock.
(13)	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.
Remarks: This report discloses a sale of shares to cover tax obligations relating to the distribution of 35,739 deferred shares under the company's Supplemental Savings and Thrift Plan (reported on August 4, 2025). In lieu of withholding for taxes, the reporting person was required to receive the full distribution of shares and subsequently sell a portion of such shares to cover his tax obligation. Exhibit List: Ex-24: Power of Attorney.

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