MPLX LP

Forward-Looking Statements

This press release contains forward-looking statements regarding MPLX LP (MPLX). These forward-looking statements may relate to, among other things, MPLX’s expectations, estimates and projections concerning its business and operations, financial priorities, including with respect to positive free cash flow and distribution coverage, strategic plans, capital return plans, capital expenditure plans, operating cost reduction objectives, and environmental, social and governance ("ESG") plans and goals, including those related to greenhouse gas emissions, biodiversity, and inclusion and ESG reporting. Forward-looking and other statements regarding our ESG plans and goals are not an indication that these statements are material to investors or required to be disclosed in our filings with the Securities Exchange Commission (SEC). In addition, historical, current, and forward-looking ESG-related statements may be based on standards for measuring progress that are still developing, internal controls and processes that continue to evolve, and assumptions that are subject to change in the future. You can identify forward-looking statements by words such as “advance,” “anticipate,” “believe,” “commitment,” “confidence," “continue,” “could,” “design,” “drive,” “endeavor,” “estimate,” “expect,” “focus,” “forecast,” “goal,” “guidance,” “intend,” “may,” “objective,” “opportunity,” “outlook,” “plan,” “policy,” “position,” “potential,” “predict,” “priority,” “progress,” “project,” “prospective,” “pursue,” “seek,” “should,” “strategy,” “strive,” “support,” “target,” “trends,” “will,” “would” or other similar expressions that convey the uncertainty of future events or outcomes. MPLX cautions that these statements are based on management’s current knowledge and expectations and are subject to certain risks and uncertainties, many of which are outside of the control of MPLX, that could cause actual results and events to differ materially from the statements made herein. Factors that could cause MPLX’s actual results to differ materially from those implied in the forward-looking statements include but are not limited to: political or regulatory developments, changes in governmental policies relating to refined petroleum products, crude oil, natural gas, natural gas liquids (“NGLs”) or renewable diesel and other renewable fuels, or taxation including changes in tax regulations or guidance promulgated pursuant to the new legislation implemented in the One Big Beautiful Bill Act; volatility in and degradation of general economic, market, industry or business conditions, including as a result of pandemics, other infectious disease outbreaks, natural hazards, extreme weather events, regional conflicts such as hostilities in the Middle East and in Ukraine, tariffs, inflation, rising interest rates or government shutdowns; the adequacy of capital resources and liquidity, including the availability of sufficient free cash flow from operations to pay or grow distributions and to fund future unit repurchases; the ability to access debt markets on commercially reasonable terms or at all; the timing and extent of changes in commodity prices and demand for crude oil, refined products, feedstocks or other hydrocarbon-based products or renewable diesel and other renewable fuels; increased pricing volatility or supply disruptions due to the U.S.-Iran conflict and market reactions thereto; changes to the expected construction costs and in service dates of planned and ongoing projects and investments, including pipeline projects and new processing units, and the ability to obtain regulatory and other approvals with respect thereto; the timing and ability to obtain necessary regulatory approvals and satisfy the other conditions necessary to consummate planned transactions within the expected timeframes if at all; the ability to realize expected returns or other benefits on planned, anticipated, ongoing, or completed projects or transactions, including the recently announced divestiture of midstream assets related to the St. Paul Park and Mandan refineries and the acquisitions of Northwind Delaware Holdings LLC and BANGL, LLC; the inability or failure of our joint venture partners to fund their share of operations and development activities; the financing and distribution decisions of joint ventures we do not control; the availability of desirable strategic alternatives to optimize portfolio assets and the ability to obtain regulatory and other approvals with respect thereto; our ability to successfully implement our sustainable energy strategy and principles and to achieve our ESG plans and goals within the expected timeframes if at all; changes in government incentives for emission-reduction products and technologies; the outcome of research and development efforts to create future technologies necessary to achieve our ESG plans and goals; our ability to scale projects and technologies on a commercially competitive basis; changes in regional and global economic growth rates and consumer preferences, including consumer support for emission-reduction products and technology; industrial incidents or other unscheduled shutdowns affecting our machinery, pipelines, processing, fractionation and treating facilities or equipment, means of transportation, or those of our suppliers or customers; the suspension, reduction or termination of MPC’s obligations under MPLX’s commercial agreements; the imposition of windfall profit taxes, maximum refining margin penalties, minimum inventory requirements or refinery maintenance and turnaround supply plans on companies operating in the energy industry in California or other jurisdictions; the establishment or increase of tariffs on goods, including crude oil and other feedstocks imported into the United States, other trade protection measures or restrictions or retaliatory actions from foreign governments; compliance costs and uncertainty associated with cap and invest programs or similar arrangements or programs in California or other jurisdictions; other risk factors inherent to MPLX’s industry; the impact of adverse market conditions or other similar risks to those identified herein affecting MPC; and the factors set forth under the heading “Risk Factors” and

“Disclosures Regarding Forward-Looking Statements” in MPLX’s and MPC's Annual Reports on Form 10-K for the year ended Dec. 31, 2025, and in other filings with the SEC.

Any forward-looking statement speaks only as of the date of the applicable communication and we undertake no obligation to update any forward-looking statement except to the extent required by applicable law.

Copies of MPLX's Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and other SEC filings are available on the SEC’s website, MPLX's website at http://ir.mplx.com or by contacting MPLX's Investor Relations office. Copies of MPC's Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and other SEC filings are available on the SEC’s website, MPC's website at https://www.marathonpetroleum.com/Investors/ or by contacting MPC's Investor Relations office.

(a) Non-GAAP measure. See reconciliation below.

(b) Beginning with the three months ended March 31, 2025, distribution coverage is defined as DCF attributable to MPLX LP divided by total LP distributions, as a result of the conversion of the remaining Series A preferred units to common units in February 2025.

(a) There were no borrowings on the loan agreement with MPC as of September 30, 2026 or December 31, 2025. Presented net of unamortized debt issuance costs, unamortized discount/premium and includes long-term debt due within one year.

(b) Calculated using face value total debt and LTM adjusted EBITDA. Face value total debt was $27,005 million as of September 30, 2026, and $26,006 million asof December 31, 2025.

(a) Includes operating data for entities that have been consolidated into the MPLX financial statements.

(b) The Utica region processing and fractionation operations only include partnership-operated equity method investments and thus do not have any operating statistics from a consolidated perspective. See table below for details on Utica.

(a) Excludes volumes associated with divested Rockies gathering and processing operations and assets contributed to Markwest EMG Jefferson Dry Gas Gathering Company, L.L.C.

(b) Includes operating data for entities that have been consolidated into the MPLX financial statements.

(a) Includes operating data for entities that have been consolidated into the MPLX financial statements as well as operating data for partnership-operated equity method investments.

(a) Excludes volumes associated with divested Rockies gathering and processing operations and assets contributed to Markwest EMG Jefferson Dry Gas Gathering Company, L.L.C.

(b) Includes operating data for entities that have been consolidated into the MPLX financial statements as well as operating data for partnership-operated equity method investments.

(a) Transaction-related costs include costs associated with the acquisition of Northwind Midstream, acquisition of the remaining interest in BANGL, LLC and the divestiture of the Rockies gathering and processing operations.

(b) Includes unrealized derivative gain/(loss), equity-based compensation, provision for income taxes and other miscellaneous items.

(a) Transaction-related costs include costs associated with the acquisition of Northwind Midstream, acquisition of the remaining interest in BANGL, LLC and the divestiture of the Rockies gathering and processing operations.

(a) Transaction-related costs include costs associated with the acquisition of Northwind Midstream, acquisition of the remaining interest in BANGL, LLC and the divestiture of the Rockies gathering and processing operations.

(b) Represents net interest and other financial costs, excluding gain/loss on extinguishment of debt and amortization of deferred financing costs.

(a) Transaction-related costs include costs associated withthe acquisition of Northwind Midstream, acquisition of the remaining interest in BANGL, LLC and the divestiture of the Rockies gathering and processing operations.

(b) Consolidated total debt excludes unamortized debt issuance costs and unamortized discount/premium. Consolidated total debt includes long-term debt due within one year and outstanding borrowings, if any, under the loan agreement with MPC.

(c) Also referred to as our leverage ratio.

(a) Represents net interest and other financial costs, excluding gain/loss on extinguishment of debt and amortization of deferred financing costs.

(b) Transaction-related costs include costs associated with the acquisition of Northwind Midstream, acquisition of the remaining interest in BANGL, LLC and the divestiture of the Rockies gathering and processing operations.

(a) The three months ended September 30, 2026 and September 30, 2025 include working capital builds of$54 million and $40 million, respectively. Thenine months ended September 30, 2026 and September 30, 2025 include working capital draws of $136 million and $43 million, respe ctively.

(a) Investments in unconsolidated affiliates and additions to property, plant and equipment are shown as separate lines within investing activities in the Consolidated Statements of Cash Flows.

(b) Return of capital for the three and nine months ended September 30, 2026 exclude $32 million in connection with the sale of ownership interest in a joint venture. Return of capital for the three and nine months ended September 30, 2025 exclude special distributions of $21 million and $42 million, respectively, received in exchange for the contribution of assets to a joint venture.

(c) Total growth capital expenditures for the three and nine months ended September 30, 2025 exclude acquisitions of $3,079 and $3,314, net of cash acquired, respectively.

(d) Growth capital reimbursements are generally included in changes in deferred revenue within operating activities in the Consolidated Statements of Cash Flows. Maintenance capital reimbursements are included in the Contributions from MPC line within financing activities in the Consolidated Statements of Cash Flows.