Sec Form 4 Filing - South Martin @ MARSH & MCLENNAN COMPANIES, INC. - 2024-03-06

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person South Martin 2. Issuer Name and Ticker or Trading Symbol MARSH & MCLENNAN COMPANIES, INC. [ MMC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) President & CEO, Marsh (Last) (First) (Middle) 1166 AVENUE OF THE AMERICAS 3. Date of Earliest Transaction (MM/DD/YY) 03/06/2024 (Street) NEW YORK 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 03/06/2024 M 11,619 A $ 0 19,250.934 D Common Stock 03/06/2024 M 4,294 A $ 0 23,544.934 D Common Stock 03/06/2024 S 3,066 D $ 203.5834 20,478.934 D Common Stock 03/06/2024 S 11,619 D $ 203.3849 ( 1 ) 8,859.934 D

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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 Stock Options (Right to Buy) $ 83.046 03/06/2024 M 11,619 ( 2 ) 02/20/2028 Common Stock 11,619 $ 0 0 D Stock Options (Right to Buy) $ 73.195 03/06/2024 M 4,294 ( 3 ) 02/21/2027 Common Stock 4,294 $ 0 0 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other South Martin 1166 AVENUE OF THE AMERICAS NEW YORK President & CEO, Marsh Signatures /s/ Tessa Patti, Attorney-in-fact 03/08/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )This transaction was executed in multiple trades at prices ranging from $203.3849 to $203.530. The price reported represents the weighted average sale price of these trades. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the shares sold at each separate price. ( 2 )These options were granted on February 21, 2018 and vested in four equal annual installments on February 21st of 2019, 2020, 2021 and 2022. ( 3 )These options were granted on February 22, 2021 and vest in four equal annual installments on February 22nd of 2022, 2023, 2024 and 2025.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* 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).

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