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 *
MAC MAHON THOMAS P
  2. Issuer Name and Ticker or Trading Symbol
Express Scripts Holding Co. [ESRX]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O EXPRESS SCRIPTS HOLDING COMPANY, ONE EXPRESS WAY
3. Date of Earliest Transaction (Month/Day/Year)
12/20/2018
(Street)

ST. LOUIS, MO 63121
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 12/20/2018   D   59,628 (1) D (1) 0 D  

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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
Non-Qualified Stock Option (Right to Buy) $ 52.53 12/20/2018   D     6,870   (2) 05/30/2019 Express Scripts Holding Company Common Stock 6,870 $ 0 (3) 0 D  
Non-Qualified Stock Option (Right to Buy) $ 61.58 12/20/2018   D     5,872   (2) 05/09/2020 Express Scripts Holding Company Common Stock 5,872 $ 0 (3) 0 D  
Non-Qualified Stock Option (Right to Buy) $ 67.05 12/20/2018   D     6,402   (2) 05/07/2021 Express Scripts Holding Company Common Stock 6,402 $ 0 (3) 0 D  
Non-Qualified Stock Option (Right to Buy) $ 84.08 12/20/2018   D     5,604   (2) 05/06/2025 Express Scripts Holding Company Common Stock 5,604 $ 0 (3) 0 D  
Non-Qualified Stock Option (Right to Buy) $ 72.74 12/20/2018   D     7,032   (2) 05/04/2026 Express Scripts Holding Company Common Stock 7,032 $ 0 (3) 0 D  
Non-Qualified Stock Option (Right to Buy) $ 60.66 12/20/2018   D     8,006   (2) 05/11/2027 Express Scripts Holding Company Common Stock 8,006 $ 0 (3) 0 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
MAC MAHON THOMAS P
C/O EXPRESS SCRIPTS HOLDING COMPANY
ONE EXPRESS WAY
ST. LOUIS, MO 63121
  X      

Signatures

 /s/ Nick H. Varsam, as Attorney-in-Fact for Thomas P. Mac Mahon   12/21/2018
**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) Pursuant to the agreement and plan of merger ("Merger Agreement") between the Issuer and Cigna Corporation, Halfmoon Parent, Inc., Halfmoon I, Inc. and Halfmoon II, Inc., upon closing of the merger of Halfmoon II, Inc. with and into the Issuer (the "Merger"), each common share of the Issuer was converted into the right to receive 0.2434 shares of Halfmoon Parent, Inc. common stock and $48.75 in cash. Each restricted stock unit was converted into a right to receive a cash payment in accordance with the payment ratio set forth in the Merger Agreement.
(2) The options vest on varying dates pursuant to the terms of the plans and/or agreements under which they were granted.
(3) Pursuant to the Merger Agreement, upon closing of the Merger, the option was converted into an option to purchase common shares of Halfmoon Parent, Inc. in accordance with the exchange ratio set forth in the Merger Agreement.

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