UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

_____________________________________________

FORM 8-K

_____________________________________________

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of ~~the~~Report ~~Securities~~(Date ~~Exchange~~of ~~Act~~earliest ofevent ~~1934~~reported) March 16, 2026

~~Date of Report (Date of earliest event reported): February~~ ~~12, 2026~~_____________________________________________

MPLX LP

(Exact name of registrant as specified in its charter)

Delaware		001-35714		27-0005456
(State or other jurisdiction of incorporation)		(CommissionFile Number)		(IRS Employer Identification No.)

_____________________________________________

Delaware

001-35714

27-0005456

(State or other jurisdiction
of incorporation)

(Commission File Number)

(IRS Employer
Identification No.)

200 E. Hardin Street, Findlay, Ohio 45840

(Address of principal executive offices) (Zip code)

Registrant’s telephone number, including area code: (419) 422-2121

_____________________________________________

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)


Securities registered pursuant to Section 12(b) of the Act:
Title of each class	Trading symbol(s)	Name of each exchange on which registered
Common Units Representing Limited Partnership Interests	MPLX	New York Stock Exchange

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class Trading symbol(s) Name of each exchangeon which registered Common Units Representing Limited Partnership Interests MPLX New York Stock Exchange


Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

~~Item~~☐ ~~8.01 Other Events.~~

~~MPLX~~Item LP5.02 ~~(the~~Departure ~~“Issuer”)~~of isDirectors ~~filing~~or ~~herewith~~Certain ~~the~~Officers; ~~following~~Election ~~exhibits~~of toDirectors; ~~its~~Appointment ~~Registration~~of ~~Statement~~Certain onOfficers; ~~Form~~Compensatory ~~S-3~~Arrangements ~~(Registration~~of ~~No. 333-271922):~~Certain Officers.

1.On ~~Underwriting~~March ~~Agreement~~16, ~~dated~~2026, MPLX GP LLC (“MPLX GP”), the general partner of MPLX LP (“MPLX” or the "Partnership"), appointed Erin M. Brzezinski as Vice President and Controller of ~~February~~MPLX 5GP, effective April 1, 2026. In this capacity, byMs. ~~and~~Brzezinski ~~among~~will be the ~~Issuer~~Partnership’s principal accounting officer. Ms. Brzezinski will succeed Rebecca L. Iten, who will cease to serve as Vice President and Controller of MPLX GP, ~~LLC~~effective April 1, 2026, and will continue to serve in an accounting leadership role for the ~~general~~Partnership. ~~partner~~This ofchange will align the ~~Issuer,~~Partnership’s accounting leadership and ~~each~~operations with Marathon Petroleum Corporation’s (“MPC”) accounting function further strengthening the integration of ~~Citigroup~~financial ~~Global~~reporting ~~Markets~~and ~~Inc~~technical accounting., ~~Barclays~~Ms. ~~Capital~~Brzezinski ~~Inc~~currently serves as the principal accounting officer of MPC and will continue to serve in that role., ~~MUFG~~Ms. ~~Securities~~Brzezinski ~~Americas~~will ~~Inc~~functionally report to C. Kristopher Hagedorn, MPLX GP’s Executive Vice President and ~~RBC~~Chief ~~Capital~~Financial ~~Markets,~~Officer ~~LLC,~~in ~~acting~~her capacity as ~~representatives~~the ofMPLX principal accounting officer and will continue reporting to Maria A. Khoury, MPC’s Executive Vice President and Chief Financial Officer in her capacity as the ~~several~~MPC ~~underwriters~~principal ~~named~~accounting ~~therein;~~officer.

2Ms. ~~Thirty-Sixth~~Brzezinski, ~~Supplemental~~age ~~Indenture~~43, ~~dated~~has served as the principal accounting officer and Vice President and Controller of ~~February~~MPC 12since January 2024. Prior to this appointment, ~~2026~~she served as MPC’s Assistant Controller, byTechnical Accounting, since August 2021, having previously served as Manager, Accounting, since 2019. Before joining MPC, Ms. Brzezinski was Director, Assurance and ~~between~~Audit ~~the~~Services, ~~Issuer~~at PricewaterhouseCoopers LLP, a professional services and ~~The~~accounting ~~Bank~~firm, ofbeginning ~~New~~in ~~York~~2018, ~~Mellon~~and ~~Trust~~Senior Manager beginning in 2013. She was Manager, Technical Accounting, at Cooper Tire & Rubber Company, Nan automotive tire manufacturer, from 2011 to 2013.A. Prior to that, asMs. ~~Trustee~~Brzezinski ~~(including~~served ~~Form~~in positions of ~~Note);~~increasing responsibility with PricewaterhouseCoopers LLP beginning in 2004.

3.MPLX ~~Thirty-Seventh~~does ~~Supplemental~~not ~~Indenture,~~directly ~~dated~~employ asany of ~~February~~the 12personnel responsible for managing and operating the MPLX business. Rather, ~~2026~~MPLX contracts with MPC to provide the necessary personnel, all of whom are directly employed by MPC or one of its wholly owned subsidiaries. Ms. Brzezinski will continue to receive an annual base salary from MPC and ~~between~~participate ~~the~~in ~~Issuer~~MPC’s annual cash bonus ("ACB") and ~~The~~long-term ~~Bank~~incentive ("LTI") programs. Descriptions of ~~New~~the ~~York~~ACB ~~Mellon~~and ~~Trust~~LTI ~~Company~~programs are included in MPLX’s Annual Report on Form 10-K for the year ended December 31, N2025 (the "2025 10-K").A Ms., Brzezinski will also continue to be eligible to participate in MPC’s other benefit plans and programs such as ~~Trustee~~health ~~(including~~and ~~Form~~life insurance, income protection in a circumstance of ~~Note);~~long-term and short-term disability, and retirement and severance benefits plans, descriptions of which are included in the 2025 10-K.

4Other than with respect to the compensation matters described above, there are no arrangements or understandings between Ms. ~~Opinion~~Brzezinski and any other persons pursuant to which Ms. Brzezinski was appointed the principal accounting officer of ~~Jones~~MPLX. ~~Day~~There are no family relationships between Ms. Brzezinski and any director or executive officer of MPLX.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

ExhibitNumber		Description
1.1		Underwriting Agreement, dated as of February 5, 2026, by and among the Issuer, MPLX GP LLC, the general partner of the Issuer, and each of Citigroup Global Markets Inc., Barclays Capital Inc., MUFG Securities Americas Inc., and RBC Capital Markets, LLC, acting as representatives of the several underwriters named therein
4.1		Thirty-Sixth Supplemental Indenture, dated as of February 12, 2026, by and between the Issuer and The Bank of New York Mellon Trust Company, N.A., as Trustee (including Form of Note)
4.2		Thirty-Seventh Supplemental Indenture, dated as of February 12, 2026, by and between the Issuer and The Bank of New York Mellon Trust Company, N.A., as Trustee (including Form of Note)
5.1		Opinion of Jones Day
23.1		Consent of Jones Day (included in Exhibit 5.1)
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	MPLX LP	~~MPLX LP~~
	By:	~~By:~~	~~MPLX GP LLC, its General Partner~~	MPLX GP LLC, its General Partner
Date: February 12, 2026		By:	/s/ Molly R. Benson
Date: March 18, 2026	By:			/s/ Molly R. Benson
		Name:	Molly R. Benson
				Name: Molly R. Benson
		Title:	Chief Legal Officer and Corporate Secretary
				Title: Chief Legal Officer and Corporate Secretary

Filing Compare · MPLX LP