Sec Form 4 Filing - SHATTUCK MAYO A III @ EXELON CORP - 2016-12-12

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 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 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 (MM/DD/YY) 12/12/2016 (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 12/12/2016 M 226,562 A $ 21.25 660,500 D Common Stock 12/12/2016 S 226,562 ( 1 ) D $ 34.63 ( 1 ) 433,938 D Common Stock 12/13/2016 M 150,000 A $ 21.25 583,938 D Common Stock 12/13/2016 S 216,289 ( 3 ) D $ 35.09 ( 2 ) 367,649 D Common Stock (401k Shares) 2,046 ( 4 ) D Common Stock 10,000 ( 5 ) I By Lizzie Mae, LLC Common Stock (Deferred stock units) 12,195 I By Exelon Directors Deferred Stock Unit 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 NQ Stock Option 02/27/2009 $ 21.25 12/12/2016 M 226,562 ( 3 ) 03/01/2018 Common Stock 226,562 ( 3 ) 150,000 D NQ Stock Option 02/27/2009 $ 21.25 12/13/2016 M 150,000 ( 3 ) 03/01/2018 Common Stock 150,000 ( 3 ) 0 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other SHATTUCK MAYO A III 10 SOUTH DEARBORN STREET 54TH FLOOR CHICAGO, IL60603 X Chairman Signatures Scott N. Peters, Attorney in Fact for Mayo A. Shattuck III 12/13/2016 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Shares were sold in lots ranging in price from $34.36 to $34.88. 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 )Shares were sold in lots ranging in price from $34.62 to $35.44. 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 )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. ( 4 )Shares held as of November 30, 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. ( 5 )Lizzie Mae, LLC, is a limited liability company of which the reporting person is the manager and to which the reporting person transferred 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.

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).

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