MPLX LP

5. Equity Method Investments

The following table presents MPLX’s equity method investments at the dates indicated:

(1)The investment in MarEn Bakken Company LLC includes our 9.19 percent indirect interest in a joint venture (“Dakota Access”) that owns and operates the Dakota Access Pipeline and Energy Transfer Crude Oil Pipeline projects (collectively, the “Bakken Pipeline system”).

(2)Included within Other are certain equity method investments that have been deemed to be VIEs. The December 31, 2024 Natural Gas and NGL Services value includes $129 million in investments associated with the Rockies, which were divested in the fourth quarter 2025.

(3)At December 31, 2024, we owned a 45 percent interest in BANGL. On July 1, 2025, we acquired the remaining 55 percent interest in BANGL. As a result of acquiring the remaining interest, we obtained control and now consolidate BANGL.

(4)On March 31, 2025, MPLX contributed a wholly-owned subsidiary with a fair value of $125 million to MarkWest EMG Jefferson Dry Gas Gathering Company, L.L.C. As a result of the transaction, MPLX received special distributions of $42 million in 2025, which are reflected as a return of capital on the Consolidated Statement of Cash Flows.

(5)MPLX also holds a 41 percent indirect interest in OGC through our ownership interest in MarkWest Utica EMG, L.L.C.

For those entities that have been deemed to be VIEs, neither MPLX nor any of its subsidiaries have been deemed to be the primary beneficiary due to voting rights on significant matters. While we have the ability to exercise influence through participation in the management committees which make all significant decisions, we have equal influence over each committee as a joint interest partner and all significant decisions require the consent of the other investors without regard to economic interest. As such, we have determined that these entities should not be consolidated and applied the equity method of accounting with respect to our investments in each entity.

MPLX’s maximum exposure to loss as a result of its involvement with equity method investments generally includes its equity investment, any additional capital contribution commitments and any operating expenses incurred by the subsidiary operator in excess of its compensation received for the performance of the operating services. MPLX did not provide any financial support to equity method investments that it was not contractually obligated to provide during the years ended December 31, 2025, 2024 and 2023. See Note 22 for information on our guarantees related to equity method investees.

From time to time, changes in the design or nature of the activities of our equity method investments may require us to reconsider our conclusions on the entity’s status as a VIE and/or our status as the primary beneficiary. Such reconsideration could result in a change in the classification of the equity method investment.

Summarized financial information for MPLX’s equity method investments is as follows:

As of December 31, 2025 and 2024, the carrying value of MPLX’s equity method investments in the Crude Oil and Products Logistics segment exceeded the underlying net assets of its investees by $283 million and $291 million, respectively. As of December 31, 2025 and 2024, the carrying value of MPLX’s equity method investments in the Natural Gas and NGL Services segment exceeded the underlying net assets of its equity method investments by approximately $124 million and $198 million, respectively.

At both December 31, 2025 and 2024, the Crude Oil and Products Logistics basis difference related to goodwill was $167 million. At December 31, 2025 and 2024, the Natural Gas and NGL Services basis difference related to goodwill was $0 million and $31 million, respectively, with the remaining basis differences primarily attributable to property, plant and equipment and intangible assets that will be amortized over the assets’ remaining useful life.