v3.26.1
Fair Value Measurements (Tables)
 3 Months Ended
Mar. 31, 2026
Fair Value Disclosures [Abstract]  
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis
The following table presents the impact on the Consolidated Balance Sheets of MPLX’s assets and liabilities measured at fair value on a recurring basis as of March 31, 2026 and December 31, 2025 by fair value hierarchy level.
March 31, 2026December 31, 2025
(In millions)Level 1Level 2Level 3Level 1Level 2Level 3
Liabilities:
Embedded derivatives in commodity contracts
Other current liabilities$— $— $11 $— $— $6 
Other long-term liabilities— — 43 — — 35 
Total embedded derivatives in commodity contracts— — 54 — — 41 
Contingent consideration / Other long-term liabilities— — 239 — — 236 
Commodity contracts - related party— 51 — — — — 
Total carrying value in Consolidated Balance Sheets$— $51 $293 $— $— $277 
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation
The following table is a reconciliation of the net beginning and ending balances recorded for net liabilities classified as Level 3 in the fair value hierarchy.
Three Months Ended 
March 31,
(In millions)20262025
Beginning balance$(277)$(58)
Unrealized and realized loss included in Net Income(1)
(17)(7)
Settlements1 3 
Ending balance$(293)$(62)
The amount of total loss for the period included in earnings attributable to the change in unrealized loss relating to liabilities still held at end of period$(18)$(7)
(1)    Gain/(loss) on derivatives embedded in commodity contracts are recorded in Purchased product costs in the Consolidated Statements of Income.
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments
March 31, 2026December 31, 2025
(In millions)Fair ValueCarrying ValueFair ValueCarrying Value
Outstanding debt(1)
$24,606 $25,813 $24,887 $25,821 
(1)    Any amounts outstanding under the MPC Loan Agreement are not included in the table above, as the carrying value approximates fair value. This balance is reflected in Current liabilities - related parties in the Consolidated Balance Sheets.