Marathon Petroleum Corp

16. Debt

Our outstanding borrowings at September 30, 2025 and December 31, 2024 consisted of the following:

MPC Senior Notes

On February 10, 2025, MPC issued $2.0 billion in aggregate principal amount of senior notes in an underwritten public offering (“2025 Senior Notes Offering”), consisting of:

•$1.1 billion aggregate principal amount of 5.150 percent senior notes due March 2030; and

•$900 million aggregate principal amount of 5.700 percent senior notes due March 2035.

The 2025 Senior Notes Offering replaced the $750 million aggregate principal amount of 3.625 percent senior notes that matured in September 2024, and the net proceeds were used to repay the $1.250 billion aggregate principal amount of 4.700 percent senior notes at maturity on May 1, 2025.

MPLX Senior Notes

On February 18, 2025, MPLX repaid all of MPLX's outstanding $500 million aggregate principal amount of 4.000 percent senior notes due February 2025 at maturity.

On March 10, 2025, MPLX issued $2.0 billion in aggregate principal amount of senior notes in an underwritten public offering (“March 2025 MPLX Senior Notes Offering”), consisting of:

•$1.0 billion aggregate principal amount of 5.400 percent senior notes due April 2035; and

•$1.0 billion aggregate principal amount of 5.950 percent senior notes due April 2055.

On April 9, 2025, MPLX used a portion of the net proceeds from the March 2025 MPLX Senior Notes Offering to redeem all of (i) MPLX LP’s outstanding $1,189 million aggregate principal amount of 4.875 percent senior notes due June 2025 and (ii) MarkWest Energy Partners, L.P.’s outstanding $11 million aggregate principal amount of 4.875 percent senior notes due June 2025. MPLX used the remaining net proceeds for general partnership purposes.

On August 11, 2025, MPLX issued $4.5 billion in aggregate principal amount of senior notes in an underwritten public offering (“August 2025 MPLX Senior Notes Offering”), consisting of:

•$1.25 billion aggregate principal amount of 4.800 percent senior notes due February 2031;

•$750 million aggregate principal amount of 5.000 percent senior notes due January 2033;

•$1.5 billion aggregate principal amount of 5.400 percent senior notes due September 2035; and

•$1.0 billion aggregate principal amount of 6.200 percent senior notes due September 2055.

MPLX used a portion of the net proceeds from the August 2025 MPLX Senior Notes Offering to fund the Northwind Midstream Acquisition, including the payment of related fees and expenses, and to increase cash and cash equivalents following the recently completed BANGL Acquisition and BANGL Debt Repayment. MPLX intends to use the remainder of the net proceeds from the August 2025 MPLX Senior Notes Offering for general partnership purposes, which may include incremental capital expenditures associated with Northwind Midstream in-process expansion projects and working capital requirements.

Capacity under our Credit Facilities as of September 30, 2025

(a) The committed borrowing and letter of credit issuance capacity under the trade receivables securitization facility is $100 million. In addition, the facility allows for the issuance of letters of credit in excess of the committed capacity at the discretion of the issuing banks.