Welcome to our dedicated page for MPLX LP SEC filings (Ticker: MPLX), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
MPLX LP filings document the disclosure record of a Delaware master limited partnership with common units representing limited partnership interests listed on the New York Stock Exchange. Its reports include 8-K disclosures for operating results and financial condition, exhibits containing earnings releases, and annual reporting on the partnership's midstream energy infrastructure and logistics business.
The filing record also covers capital-structure and financing matters, including revolving credit agreements, underwriting agreements, supplemental indentures, and debt-securities exhibits filed under registration statements. Governance disclosures address MPLX GP LLC as general partner, board and officer changes, compensatory arrangements, shareholder voting matters, material-event reporting, and risk disclosure tied to the partnership's operations and securities.
SURMA JOHN P reported acquisition or exercise transactions in this Form 4 filing.
MPLX LP director John P. Surma received an equity grant of 2,579.543 Common Units (limited partner interests) as his annual 2026 equity retainer award. The award was recorded at a price of $0.00 per unit, indicating it was compensation rather than a market purchase.
Following this grant, Surma directly holds a total of 91,769.802 MPLX Common Units. This filing reflects routine board compensation and does not show any open-market buying or selling activity.
STICE J MICHAEL reported acquisition or exercise transactions in this Form 4 filing.
MPLX LP director J. Michael Stice received an equity grant of 2,579.543 Common Units (Limited Partner Interests) on an award valued at $0.0000 per unit. This represents his annual 2026 equity retainer award. Following the grant, he directly holds 55,874.697 common units and indirectly holds 700 common units through The Mike Stice Trust.
SEMPLE FRANK M reported acquisition or exercise transactions in this Form 4 filing.
MPLX LP director Frank M. Semple reported an equity award and updated holdings in common units. He received 2,579.543 common units as his annual 2026 equity retainer award at a stated price of $0.00 per unit, increasing his direct holdings to 60,751.877 units. The filing also lists indirect ownership of MPLX common units through EK Holdings LLC, the Robin Y Semple 2012 Dynasty Trust, and the Frank M Semple Revocable Trust.
Peiffer Garry L. reported acquisition or exercise transactions in this Form 4 filing.
MPLX LP director Garry L. Peiffer received an equity compensation award of 2,246.989 common units of MPLX LP on April 30, 2026. The award was granted at $0.00 per unit as his annual 2026 equity retainer, so it was not an open-market purchase.
After this grant, Peiffer directly holds 66,319.332 common units. Separately, 68,497 common units are reported as indirectly held through the Garry L. Peiffer Revocable Trust.
HELMS CHRISTOPHER A reported acquisition or exercise transactions in this Form 4 filing.
MPLX LP director Christopher A. Helms received an equity grant of 2,246.989 common units as part of his annual 2026 equity retainer award. The grant was reported at a price of $0.00 per unit, reflecting a compensation award rather than a market purchase. Following this award, Helms directly holds a total of 82,998.086 MPLX common units.
Breves Christine S reported acquisition or exercise transactions in this Form 4 filing.
MPLX LP director Christine S. Breves received an equity grant of 2,246.989 common units (limited partner interests) as her annual 2026 equity retainer award. The grant was reported at a price of $0.00 per unit, indicating it is compensation rather than an open-market purchase. Following this award, she directly holds a total of 14,084.446 MPLX common units.
MPLX LP entered into a new $2.5 billion unsecured revolving credit agreement maturing on April 7, 2031, intended for general partnership purposes. This New MPLX Credit Agreement replaces the prior $2.0 billion 2022 credit facility, which was terminated with no borrowings outstanding.
The facility has a $2.5 billion commitment with the option to increase commitments by up to an additional $1.0 billion, subject to lender consent. It includes sub-facilities for $150 million of swing-line loans and up to $150 million of letters of credit, which may be increased to $200 million.
Borrowings accrue interest at either Adjusted Term SOFR plus 100–175 basis points or an Alternate Base Rate plus 0–75 basis points, depending on MPLX’s credit ratings. MPLX must keep its ratio of Consolidated Total Debt to Consolidated EBITDA at or below 5.0x, or 5.5x during an Acquisition Period. As of March 31, 2026, MPLX reported $1.5 billion of cash and cash equivalents and no borrowings under the new facility.
MPLX LP officer Erin M. Brzezinski, VP and Controller, reported her ownership of the partnership’s common units. The filing shows she holds 4,733 Common Units (Limited Partner Interests) directly. The entry is categorized as a holding, with no reported purchases, sales, or derivative positions.
MPLX LP is changing its top accounting leadership structure. Effective April 1, 2026, Erin M. Brzezinski will become Vice President and Controller of MPLX GP LLC and serve as the Partnership’s principal accounting officer, succeeding Rebecca L. Iten, who will move to another accounting leadership role at the Partnership.
The move is designed to better align MPLX’s accounting leadership and operations with Marathon Petroleum Corporation (MPC). Brzezinski already serves as MPC’s principal accounting officer and Vice President and Controller and will retain those responsibilities, reporting to the CFOs of both MPLX GP and MPC in her respective roles.
MPLX does not directly employ its personnel and instead contracts with MPC, so Brzezinski will continue to receive salary, bonuses, long-term incentives and benefits from MPC under its existing compensation and benefit programs described in MPLX’s 2025 annual report.
MPLX LP director and Chairman, President & CEO Maryann T. Mannen reported several equity transactions in common units. On March 1, 2026, she acquired 52,817 common units as a grant or award at a stated price of $0.0000 per unit. On March 2, 2026, she had three tax-withholding dispositions totaling several thousand units at $59.2200 per unit, used to satisfy exercise price or tax liabilities rather than open-market sales. Following these transactions, her direct holdings in MPLX common units remained significant, with reported balances after each step in the sequence.