FORM 4 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 OF SECURITIES 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 * O'Brien Denis P.   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 __X__ Officer (give title below) _____ Other (specify below) Executive Vice President (Last) (First) (Middle) 10 SOUTH DEARBORN STREET, 54TH FLOOR 3. Date of Earliest Transaction (Month/Day/Year) 11/20/2012 (Street) CHICAGO, IL 60603 4. If Amendment, Date Original Filed(Month/Day/Year) 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 (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 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 11/20/2012   M   30,000 (1) A $ 24.805 40,287 D   Common Stock 11/20/2012   S   30,000 (1) D $ 29.06 (2) 10,287 D   Common Stock - ESPP               1,405 D   Common Stock (Deferred Shares)               7,550 (3) I By Stock Deferral Plan Common Stock               20,000 I Held by spouse.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

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 (Month/Day/Year)

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

NQ Stock Options 01/27/2003

$ 24.805

11/20/2012

M(1)

30,000

(4)

(4)

Common Stock

30,000

(4)

0

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
O'Brien Denis P. 10 SOUTH DEARBORN STREET 54TH FLOOR CHICAGO, IL 60603			Executive Vice President

Signatures

Scott N. Peters, Attorney in Fact for Denis P. O'Brien		11/20/2012
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	Exercise and sale made pursuant to a Rule 10b5-1 Sale Plan entered into on 06/12/2012.
(2)	Shares were sold in lots ranging in price from $28.96 to $29.21. The filer undertakes to provide upon request by the SEC Staff, the issuer, or a security holder of the issuer, full information rgarding the number of shares purchased or sold at each separate price.
(3)	Balance includes 98 shares acquired on 3/10/2012, 28 shares acquired on 4/11/2012, 75 shares acquired on 6/8/2012 and 109 shares acquired on 9/10/2012 through automatic dividend reinvestment.
(4)	Non qualified employee stock options, awarded pursuant to the Exelon Long Term Incentive Plan. Options vested in 1/3 increments on each of the first two anniversaries of the grant date, referenced in column one, and would expire on the tenth anniversay of the grant date.

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