Ownership Submission
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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(Print or Type Responses)
1. Name and Address of Reporting Person *
SHATTUCK MAYO A III
  2. Issuer Name and Ticker or Trading Symbol
EXELON CORP [EXC]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) __X__ Other (specify below)
Chairman
(Last)
(First)
(Middle)
10 SOUTH DEARBORN STREET, 54TH FLOOR
3. Date of Earliest Transaction (Month/Day/Year)
05/12/2016
(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 05/12/2016   M   350,000 A $ 21.25 760,938 D  
Common Stock 05/12/2016   S   327,000 (1) D $ 35.3 433,938 D  
Common Stock (401k Shares)               1,989 (3) D  
Common Stock               78,519 (4) I By Lizzie Mae, LLC
Common Stock (Deferred stock units)               10,300 I By Exelon Directors Deferred Stock Unit Plan

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 Option 02/27/2009 $ 21.25 05/12/2016   M     350,000 (1)   (2) 03/01/2018 Common Stock 350,000 (2) 376,562 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
SHATTUCK MAYO A III
10 SOUTH DEARBORN STREET
54TH FLOOR
CHICAGO, IL 60603
  X     Chairman

Signatures

 Scott N. Peters, Attorney in Fact for Mayo A. Shattuck III   05/12/2016
**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) Shares were sold in lots ranging in price from $35.00 to $35.56. 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.
(2) Exercise of fully-vested non-qualified employee stock options that expire on March 1, 2018. Options were originally granted by Constellation Energy Group that vested and were converted pursuant to the Merger Agreement. Each Constellation option was converted into an option to purchase Exelon common stock at the rate of 0.93 shares of Exelon common stock for each share of Constellation common stock at a strike price equal to the quotient of the original Constellation strike price and 0.93.
(3) Shares held as of April 29, 2016 in a multi-fund 401(k) Plan to be settled in 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.
(4) Lizzie Mae, LLC, is a limited liability company of which the reporting person is the manager and to which the reporting person transferred 78,519 shares of his Exelon common stock. On December 18, 2012, the reporting person transferred 1/3 membership interests in Lizzie Mae, LLC, to each of three trusts, each one for the benefit of one of the reporting person's three minor children. The reporting person's wife is a trustee of each of the trusts. The reporting person disclaims beneficial ownership of the Exelon Corporation common stock held by Lizzie Mae LLC except to the extent of his pecuniary interest therein.

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