Sec Form 5 Filing - MEHRBERG RANDALL E @ EXELON CORP - 2007-12-31

FORM 5 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person MEHRBERG RANDALL E 2. Issuer Name and Ticker or Trading Symbol EXELON CORP [ EXC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner _____ Officer (give title below) X __ Other (specify below) Exec. Officer thru 12-31-2007 (Last) (First) (Middle) 10 SOUTH DEARBORN STREET, 54TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 12/31/2007 (Street) CHICAGO, IL60603 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock - Deferred Shares 67,401 ( 1 ) I By Stock Deferral Plan

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Performance Shares - Stock Units ( 2 ) ( 2 ) ( 2 ) Common Stock 28,134 28,134 ( 3 ) D Deferred Comp. Phantom Shares ( 4 ) ( 4 ) ( 4 ) Common Stock 237 237 D NQ Stock Options 01/26/2004 $ 32.54 ( 5 ) ( 5 ) Common Stock 40,000 40,000 D NQ Stock Options 01/24/2005 $ 42.85 ( 5 ) ( 5 ) Common Stock 56,000 56,000 D NQ Stock Options 01/23/2006 $ 58.55 ( 5 ) ( 5 ) Common Stock 35,000 35,000 D NQ Stock Options 01/22/2007 $ 59.96 ( 5 ) ( 5 ) Common Stock 35,000 35,000 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other MEHRBERG RANDALL E 10 SOUTH DEARBORN STREET 54TH FLOOR CHICAGO, IL60603 Exec. Officer thru 12-31-2007 Signatures Randall E. Mehrberg 01/29/2008 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Balance includes 441 shares acquired on 03/10/2007, 403 shares on 06/11/2007, 399 shares on 09/10/2007 and 343 shares on 12/10/2007 through the automatic dividend reinvestment feature of Exelon plans. ( 2 )Performance Shares awarded pursuant to the Exelon Long Term Incentive Plan. 1/3 of the shares awarded vested immediately upon receipt. The remaining shares vest in 1/3 increments on each of the first and second anniversaries of the grant date. Under certain circumstances some or all of the vested shares may be settled in cash on a 1 for 1 basis based on the cash value of the underlying stock on the date of vesting. ( 3 )Balance includes 184 shares acquired on 03/10/2007, 168 shares on 06/11/2007, 167 shares on 09/10/2007 and 143 shares on 12/10/2007 through the automatic dividend reinvestment feature of Exelon plans. ( 4 )Phantom shares held in a multi-fund deferred compensation plan to be settled for cash upon the reporting person's termination of employment for any reason on a 1:1 basis. Shares are acquired through regular periodic contributions, company matching contributions, and the automatic reinvestment of dividends. ( 5 )Non qualified employee stock options, awarded pursuant to the Exelon Long Term Incentive Plan. Options vest in 1/4 increments on each of the first four anniversaries of the grant date, referenced in column one, and expire on the tenth anniversay of the grant date.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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