X0508 4 2025-09-01 0000008670 AUTOMATIC DATA PROCESSING INC ADP 0001608466 Black Maria ONE ADP BOULEVARD ROSELAND NJ 07068 1 President & CEO 1 Common Stock 2025-09-01 4 A 0 19000.0000 0.0000 A 124485.0445 D Common Stock 2025-09-02 4 M 0 7721.0000 206.8600 A 132206.0445 D Common Stock 2025-09-02 4 S 0 638.0000 302.0154 D 131568.0445 D Common Stock 2025-09-02 4 S 0 1678.0000 301.2903 D 129890.0445 D Common Stock 2025-09-02 4 S 0 2228.0000 299.5828 D 127662.0445 D Common Stock 2025-09-02 4 S 0 3177.0000 299.0418 D 124485.0445 D Common Stock 2025-09-02 4 F 0 24718.8860 304.0500 D 99766.1585 D Stock Option (Right to Buy) 206.8600 2025-09-02 4 M 0 7721.0000 206.8600 D 2022-09-01 2031-08-31 Common Stock 7721.0000 0.0000 D In the form of restricted stock units, which are convertible into common stock on a one-for-one basis and vest ratably over 3 years. The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person in September 2024. David Kwon (POA on File) 2025-09-03