X0306 4 2020-12-31 0001109357 EXELON CORP EXC 0001257061 DE BALMANN YVES C 10 SOUTH DEARBORN STREET 54TH FLOOR CHICAGO IL 60603 1 0 0 0 Common Stock (Deferred Stock Units) 2020-12-31 4 A 0 941 41.20 A 34565 I By Exelon Directors' Deferred Stock Unit Plan Common stock 1910 D Phantom Stock Units Common Stock 42645 42645 I By CEG Deferred Compensation Plan for Non-employee Directors Balance includes 309 shares acquired on December 10, 2020 through automatic dividend reinvestment. Phantom deferred stock units converted from the legacy Constellation Energy Group Inc. (CEG) Deferred Compensation Plan for Non-employee Directors to be settled in cash on a 1 for 1 basis upon the termination of the reporting person's service on the Exelon board of directors. Balance updated to reflect 392 additional stock units credited on December 10, 2020 through the dividend reinvestment feature of the plan. Elizabeth M. Hensen, Attorney in Fact for Yves C. de Balmann 2020-12-31