Arthur J. Gallagher & Co. (AJG) FWP Free writing prospectus

Issuer Free Writing Prospectus

Dated February 12, 2024

Filed Pursuant to Rule 433 relating to the

Preliminary Prospectus Supplement dated February 12, 2024 and

Prospectus dated February 12, 2024

Registration Statement No. 333-277002

$1,000,000,000

$500,000,000 5.450% Senior Notes due 2034 (the “2034 Notes”)

$500,000,000 5.750% Senior Notes due 2054 (the “2054 Notes”)

Issuer:	Arthur J. Gallagher & Co.
Expected Ratings
(Moody’s/S&P/Fitch)*:	Baa2 (stable) / BBB (stable) / BBB+ (stable)
Security Type:	Senior, Unsecured
Principal Amount:	2034 Notes: $500,000,000
	2054 Notes: $500,000,000
Issue Price:	2034 Notes: 99.722% plus accrued interest, if any, from February 15, 2024
	2054 Notes: 98.788% plus accrued interest, if any, from February 15, 2024
Proceeds to Issuer (after underwriting
discount but before offering expenses):	2034 Notes: $495,360,000
	2054 Notes: $489,565,000
Trade Date:	February 12, 2024
Settlement Date:	February 15, 2024 (T+3)
Maturity Date:	2034 Notes: July 15, 2034
	2054 Notes: July 15, 2054
Coupon:	2034 Notes: 5.450% per annum
	2054 Notes: 5.750% per annum
Interest Payment Dates:	2034 Notes: Semi-annually on January 15 and July 15 of each year, commencing on July 15, 2024 (short first interest payment)

	2054 Notes: Semi-annually on January 15 and July 15 of each year, commencing on July 15, 2024 (short first interest payment)
Benchmark Treasury:	2034 Notes: 4.000% due February 15, 2034
	2054 Notes: 4.750% due November 15, 2053
Benchmark Treasury Price/Yield:	2034 Notes: 98-21 / 4.166%
	2054 Notes: 106-11+ / 4.366%
Spread to Benchmark Treasury:	2034 Notes: 132 basis points
	2054 Notes: 147 basis points
Yield to Maturity:	2034 Notes: 5.486%
	2054 Notes: 5.836%
Optional Redemption:	2034 Notes: Prior to April 15, 2034, make-whole call at the greater of 100% of the principal amount of the 2034 Notes to be redeemed and the discounted present value through the par call date at the applicable Treasury Rate plus 20 basis points, plus accrued and unpaid interest
	On or after April 15, 2034, par call plus accrued and unpaid interest
	2054 Notes: Prior to January 15, 2054, make-whole call at the greater of 100% of the principal amount of the 2054 Notes to be redeemed and the discounted present value through the par call date at the applicable Treasury Rate plus 25 basis points, plus accrued and unpaid interest
	On or after January 15, 2054, par call plus accrued and unpaid interest
Change of Control:	Upon certain change of control events, at 101% of the principal amount of Notes, plus accrued and unpaid interest.
Use of Proceeds:	The Issuer expects to use the net proceeds of this offering for general corporate purposes, which may include acquisitions, repayment of outstanding indebtedness, capital expenditures, working capital, and stock repurchases.
CUSIP/ISIN:	2034 Notes: 04316J AH2 / US04316JAH23
	2054 Notes: 04316J AJ8 / US04316JAJ88
Joint Book-Running Managers:	BofA Securities, Inc.
	J.P. Morgan Securities LLC
	Barclays Capital Inc.

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	BMO Capital Markets Corp.
	Citigroup Global Markets Inc.
	Morgan Stanley & Co. LLC
Co-Managers:	Capital One Securities, Inc.
	HSBC Securities (USA) Inc.
	Lloyds Securities Inc.
	Wells Fargo Securities, LLC
	PNC Capital Markets LLC

*Ratings may be changed, suspended or withdrawn at any time and are not a recommendation to buy, hold or sell any security.

The issuer has filed a registration statement (including a prospectus and a preliminary prospectus supplement) with the Securities and Exchange Commission for the offering to which this communication relates. Before you invest, you should read the prospectus and the preliminary prospectus supplement in that registration statement and other documents the issuer has filed with the Securities and Exchange Commission for more complete information about the issuer and this offering. You may get these documents for free by visiting EDGAR on the Securities and Exchange Commission’s website at www.sec.gov. Alternatively, the issuer, any underwriter or any dealer participating in the offering will arrange to send you the prospectus and preliminary prospectus supplement if you request it by calling BofA Securities, Inc. at 1-800-294-1322 or J.P. Morgan Securities LLC at 1-212-834-4533.

We expect that delivery of the Notes will be made against payment therefor on or about the closing date specified in this communication, which will be the third business day following the Trade Date (this settlement cycle being referred to as “T+3”). Under Rule 15c6-1 of the Securities Exchange Act of 1934, as amended, trades in the secondary market generally are required to settle in two business days, unless the parties to any such trade expressly agree otherwise. Accordingly, investors who wish to trade the Notes on the Trade Date, by virtue of the fact that the Notes initially will settle T+3, should specify an alternative settlement arrangements at the time of any such trade to prevent a failed settlement. Purchasers of Notes who wish to trade the Notes on the Trade Date should consult their own advisors.

ANY DISCLAIMERS OR OTHER NOTICES THAT MAY APPEAR BELOW ARE NOT APPLICABLE TO THIS COMMUNICATION AND SHOULD BE DISREGARDED. SUCH DISCLAIMERS OR OTHER NOTICES WERE AUTOMATICALLY GENERATED AS A RESULT OF THIS COMMUNICATION BEING SENT VIA BLOOMBERG OR ANOTHER E-MAIL SYSTEM.

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