MPLX LP

6. Equity

The changes in the number of common units during the nine months ended September 30, 2026 are summarized below:

Unit Repurchase Program

As of September 30, 2026, we had $970 million remaining under the unit repurchase authorization. Total unit repurchases were as follows for the respective periods:

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

Series A Redeemable Preferred Unit Conversions

On February 11, 2025, MPLX exercised its right to convert the remaining 6 million outstanding Series A preferred units into common units in accordance with the conversion provision outlined in our Sixth Amended and Restated Agreement of Limited Partnership.

Cash Distributions

On October 27, 2026, MPLX declared a cash distribution for the third quarter of 2026, totaling $1,226 million, or $1.2111 per common unit. This distribution will be paid on November 13, 2026 to common unitholders of record on November 6, 2026. Although our partnership agreement requires that we distribute all of our available cash (as defined in the partnership agreement) each quarter, we do not otherwise have a legal obligation to distribute any particular amount per common unit.

The allocation of total quarterly cash distributions is as follows for the three and nine months ended September 30, 2026 and September 30, 2025. Distributions are not accrued until declared. MPLX’s distributions are declared 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.