X0306 4/A 2020-08-10 2020-08-12 0 0001564406 Oak Street Health, Inc. ?OSH? 0001793307 HISKES CYNTHIA C/O OAK STREET HEALTH, INC. 30 W. MONROE STREET, SUITE 1200 CHICAGO IL 60603 0 1 0 0 Chief Human Resources Officer Common stock, $0.001 par value 2020-08-10 4 P 0 120 21.00 A 277180 D Represents shares purchased in the Issuer's directed share program upon the closing of the Issuer's initial public offering, which closed on August 10, 2020. These shares were omitted from the Reporting Person's previous form 4. /s/ Robert Guenthner, as attorney-in-fact for Cynthia Hiskes 2020-08-28