X0201 4 2004-03-31 0001109357 EXELON CORP EXC 0001178439 GRECO ROSEMARIE B 10 SOUTH DEARBORN STREET 37TH FLOOR CHICAGO IL 60603 1 0 0 0 Common Stock (Deferred Stock Units) 2004-03-31 4 A 0 184 67.83 A 3234 I By Exelon Directors' Deferred Stock Unit Plan Common Stock (Deferred Stock Units) 2605 I By PECO Energy Directors' Stock Unit Plan Common Stock 1000 D Deferred Comp. Phantom Shares Common Stock 2257 2257 D Balance also includes 25 shares acquired on 03/10/2004 through the automatic dividend reinvestment feature of Exelon plans. Balance also includes 21 shares acquired on 03/10/2004 through the automatic dividend reinvestment feature of Exelon plans. Phantom shares held in a multi-fund deferred compensation account to be settled for cash on a 1:1 basis upon the reporting person's termination of employment for any reason. Shares are acquired through regular periodic contributions and the reinvestment of dividend equivalents. Balance includes 18 shares acquired on 03/10/2004 through the automatic dividend reinvestment feature of Exelon plans. Bruce G. Wilson, Attorney in Fact for Rosemarie B. Greco 2004-04-01