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 * Heminger Gary R.   2. Issuer Name and Ticker or Trading Symbol MPLX LP [MPLX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Chairman, CEO (Last) (First) (Middle) C/O MPLX LP, 200 E. HARDIN STREET 3. Date of Earliest Transaction (Month/Day/Year) 12/20/2018 (Street) FINDLAY, OH 45840 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 Units (Limited Partner Interests) 12/20/2018   A   5,265 A $ 31.255 105,984 (1) D   Common Units (Limited Partner Interests) 12/20/2018   F   3,167 D $ 31.255 102,817 D   Common Units (Limited Partner Interests)               26,750 I By Revocable Trust (2) Common Units (Limited Partner Interests)               1,576.612 (3) (4) I As UTMA custodian for minor grandchild 1 Common Units (Limited Partner Interests)               1,576.612 (3) (4) I As UTMA custodian for minor grandchild 2 Common Units (Limited Partner Interests)               1,576.612 (3) (4) I As UTMA custodian for minor grandchild 3 Common Units (Limited Partner Interests)               1,576.612 (3) (4) I As UTMA custodian for minor grandchild 4 Common Units (Limited Partner Interests)               1,576.612 (3) (4) I As UTMA custodian for minor grandchild 5 Common Units (Limited Partner Interests)               1,500 (3) (4) I As UTMA custodian for minor grandchild 6 Common Units (Limited Partner Interests)               95,780 (5) I By GRAT (6)

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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

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Heminger Gary R. C/O MPLX LP 200 E. HARDIN STREET FINDLAY, OH 45840	X		Chairman, CEO

Signatures

/s/ Molly R. Benson, Attorney-in-Fact for Gary R. Heminger		12/26/2018
**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)	Adjusted to reflect the fact the tax withholding reported on the Form 4 filed on October 3, 2018 did not occur and adjusted per footnote five below.
(2)	By Gary R. Heminger Revocable Trust.
(3)	The reporting person disclaims beneficial ownership of these units, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.
(4)	The units are held in UTMA accounts for the benefit of Mr. Heminger's minor grandchildren. Mr. Heminger is the custodian and maintains investment control over the accounts.
(5)	On December 21, 2018 the Reporting Person contributed 95,780 units to a grantor retained annuity trust ("GRAT") for the benefit of himself and his two adult children. These trust holdings consist of those units, which were previously reported as directly owned on prior Forms 4.
(6)	By Gary R. Heminger Irrevocable GRAT.
Remarks: The Reporting Person is the Chairman of the Board of Directors and the Chief Executive Officer of MPLX GP LLC, the general partner of the Issuer. The Issuer is managed by the directors and executive officers of MPLX GP LLC.

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