X0607 3/A 2026-04-15 2026-04-24 0 0001004434 AFFILIATED MANAGERS GROUP, INC. AMG 0002129201 Patel Cheerag B. false C/O AFFILIATED MANAGERS GROUP, INC. 1001 U.S. HIGHWAY ONE NORTH JUPITER FL 33477 1 Head of Affiliate Engagement Stock Units 0 Common Stock 2751 D Reflects restricted stock units subject to vesting from 2027 to 2030; 1,261 in March 2027, 795 in March 2028, 498 in March 2029, and 197 in March 2030. These restricted stock units were inadvertently omitted from the reporting person's original Form 3. /s/ Kavita Padiyar, Attorney-in-Fact 2026-06-26