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.
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.
MPLX LP Senior VP of Logistics & Storage Shawn M. Lyon reported equity compensation and related tax transactions in common units. On March 1, 2026, he acquired 5,986 common units as a grant at $0.00 per unit. On March 2, 2026, he had three F-code tax-withholding dispositions of 920, 1,033, and 798 common units at $59.22 per unit to satisfy tax obligations by delivering units. After these transactions, he directly held 28,289 common units of MPLX LP.
MPLX LP director Maria A. Khoury reported an award of 8,451 Common Units (Limited Partner Interests). The units were acquired as a grant or award at a stated price of $0.00 per unit, bringing her directly held total to 8,451 units.
MPLX LP executive vice president and chief financial officer Carl Kristopher Hagedorn reported both an equity award and related tax-withholding transactions in common units. On March 1, 2026, he acquired 4,930 common units as a grant at $0.00 per unit. On March 2, 2026, he disposed of 422, 916, and 663 common units at $59.22 per unit in tax-withholding dispositions. Following these transactions, his direct holdings were reported at 20,409 common units.