X0306 4 2023-02-28 0000062709 MARSH & MCLENNAN COMPANIES, INC. MMC 0001838241 Fernandez Carmen 1166 AVENUE OF THE AMERICAS NEW YORK NY 10036 1 SVP, Chief People Officer Common Stock 244.179 I MMC 401(k) Savings & Investment Plan Common Stock 2023-02-28 4 M 0 1544 0 A 3389 D Common Stock 2023-02-28 4 F 0 855 162.83 D 2534 D Restricted Stock Units 2023-02-28 4 M 0 1544 0 D Common Stock 1544 0 D Reflects shares acquired by the Marsh & McLennan Companies 401(k) Savings & Investment Plan (SIP) Custodian at prevailing market prices. Information reported herein is based on reporting person's Plan Statement as of December 31, 2022. Vesting and distribution to reporting person of 1,544 shares underlying restricted stock units of which 855 were withheld by Marsh & McLennan Companies to cover applicable taxes. These 1,544 shares underlying restricted stock units relate to 386 restricted stock units that were granted on February 19, 2020, and 1,158 restricted stock units relating to performance stock units that were granted on February 19, 2020 for the performance period 2020-2022. The security converts to Marsh & McLennan Companies common stock on a 1-for-1 basis. Not Applicable /s/ Tessa Patti, Attorney-in-fact 2023-03-02