MPLX LP

7. Equity

Units Outstanding

MPLX had 1,015,702,040 common units outstanding as of December 31, 2025. Of that number,647,415,452 were owned by MPC. The changes in the number of common units during the years ended December 31, 2023, 2024 and 2025 are summarized below:

(1) Certain Series A preferred unitholders have exercised their rights to convert their Series A preferred units into common units as discussed in Note 9.

Unit Repurchase Program

On August 5, 2025, we announced a board authorization for the repurchase of $1.0 billion of MPLX common units held by the public in addition to the $1.0 billion common unit repurchase authorization announced on August 2, 2022. These unit repurchase authorizations have no expiration date. We may utilize various methods to effect the repurchases, which could include open market repurchases, negotiated block transactions, accelerated unit repurchases, tender offers or open market solicitations for units, some of which may be effected through Rule 10b5-1 plans. The timing and amount of future repurchases, if any, will depend upon several factors, including market and business conditions, and such repurchases may be suspended, discontinued or restarted at any time.

Total unit repurchases were as follows for the years ended December 31, 2025, 2024 and 2023:

(1)Cash paid for common units repurchased and average cost per unit includes commissions paid to brokers during the period.

As of December 31, 2025, we had $1,120 million remaining under the unit repurchase authorizations.

Redemption of the Series B Preferred Units

On February 15, 2023, MPLX exercised its right to redeem all 600,000 units of 6.875 percent Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (the “Series B preferred units”). MPLX paid unitholders the Series B preferred unit redemption price of $1,000 per unit. MPLX made a final cash distribution of $21 million to Series B preferred unitholders on February 15, 2023, in conjunction with the redemption.

The changes in the Series B preferred unit balance during 2023 are included in the Consolidated Statements of Equity within Series B preferred units.

Cash Distributions

Total distributions declared for the years ended December 31, 2025, 2024 and 2023 are summarized in the table below.

The allocation of total quarterly cash distributions to common and preferred unitholders is as follows for the years ended December 31, 2025, 2024 and 2023. The Sixth Amended and Restated Agreement of Limited Partnership, dated as of February 1, 2021 (“Partnership Agreement”) sets forth the calculation to be used to determine the amount and priority of cash distributions that the common unitholders and preferred unitholders will receive. MPLX’s distributions are declared for the prior quarter subsequent to the quarter end; therefore, the following table represents total cash distributions applicable to the period for which the distributions relate as opposed to the quarter in which they were declared and paid.

(1)2023 period includes the portion of the $21 million distribution paid to the Series B preferred unitholders on February 15, 2023 that was earned during the period prior to the redemption.

On January 29, 2026, MPLX declared a quarterly cash distribution, based on the results of the fourth quarter of 2025, totaling $1,092 million, or $1.0765 per common unit. This distribution was paid on February 17, 2026 to unitholders of record on February 9, 2026.