X0508 4 2025-03-04 0000062709 MARSH & MCLENNAN COMPANIES, INC. MMC 0001901227 South Martin 1166 AVENUE OF THE AMERICAS NEW YORK 1 President & CEO, Marsh 0 Common Stock 2025-03-04 4 S 0 2000 239.9635 D 17062.517 D Common Stock 2025-03-04 4 M 0 12620 90.785 A 29682.517 D Common Stock 2025-03-04 4 M 0 11856 118.865 A 41538.517 D Common Stock 2025-03-04 4 S 0 11856 239.4707 D 29682.517 D Common Stock 2025-03-04 4 S 0 6028 239.1988 D 23654.517 D Common Stock 2025-03-04 4 S 0 6592 240.0413 D 17062.517 D Stock Options (Right to Buy) 90.785 2025-03-04 4 M 0 12620 0 D 2029-02-18 Common Stock 12620 0 D Stock Options (Right to Buy) 118.865 2025-03-04 4 M 0 11856 0 D 2030-02-18 Common Stock 11856 0 D This transaction was executed in multiple trades at prices ranging from $239.840 to $239.970. 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. This transaction was executed in multiple trades at prices ranging from $239.040 to $239.830. 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. This transaction was executed in multiple trades at prices ranging from $238.610 to $239.600. 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. This transaction was executed in multiple trades at prices ranging from $239.720 to $240.460. 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. These options were granted on February 19, 2019 and vested in four equal annual installments on February 19, 2020, 2021, 2022 and 2023. These options were granted on February 19, 2020 and vested in four equal annual installments on February 19, 2021, 2022, 2023 and 2024. /s/ Tessa Patti, Attorney-in-fact 2025-03-05