MPLX LP

Auditor Independence

Our Audit Committee has considered whether PricewaterhouseCoopers LLP is independent for purposes of providing external audit services to us and has determined that it is.

Auditor Fees

Following are the aggregate fees for professional services provided to us by PricewaterhouseCoopers LLP for the years ended December 31, 2025, and December 31, 2024:

Audit fees for the years ended December 31, 2025, and December 31, 2024, were primarily for professional services rendered for the audit of the financial statements and of internal control over financial reporting, the performance of regulatory audits, issuance of comfort letters, the provision of consents and the review of documents filed with the SEC.

Tax fees for the years ended December 31, 2025, and December 31, 2024, were for professional services rendered for the preparation of IRS Schedule K-1 tax forms for MPLX LP unitholders and for income tax consultation services.

Pre-Approval of Audit Services

Our Pre-Approval of Audit, Audit-Related, Tax and Permissible Non-Audit Services Policy sets forth the procedure for the Audit Committee to pre-approve all audit, audit-related, tax and permissible non-audit services, other than as provided under a de minimis exception. Our general partner’s chief financial officer annually presents the Audit Committee with a forecasted budget of audit, audit-related, tax and permissible non-audit services, and updates the Committee throughout the year as needed. The Audit Committee may pre-approve any services to be performed by our independent auditor up to 12 months in advance and may pre-approve services by specific categories pursuant to the forecasted budget. For unbudgeted items, the Audit Committee has delegated pre-approval authority of up to $250,000 to the Audit Committee Chair. Items approved in this manner are reported to the full Audit Committee at its next scheduled meeting. The pre-approval policy is available on our website atwww.mplx.com/Investors/Corporate-Governance/.

In 2025 and 2024, the Audit Committee pre-approved all audit, audit-related, tax and permissible non-audit services pursuant to this policy and did not use the de minimis exception.