Financial Highlights (unaudited)

Segment Results

Crude Oil and Products Logistics

Natural Gas and NGL Services

Strategic Update

Newly Announced

Ongoing

2025 Capital Outlook

Financial Position and Liquidity

Conference Call

About MPLX LP

Investor Relations Contact: (419) 421-2071

Media Contact: (419) 421-3577

Non-GAAP references

In addition to our financial information presented in accordance with U.S. generally accepted accounting principles (GAAP), management utilizes additional non-GAAP measures to analyze our performance. This press release and supporting schedules include the non-GAAP measures adjusted EBITDA; consolidated debt to last twelve months adjusted EBITDA, which we refer to as our leverage ratio; distributable cash flow (DCF); adjusted free cash flow (Adjusted FCF); and Adjusted FCF after distributions.

Adjusted EBITDA is a financial performance measure used by management, industry analysts, investors, lenders, and rating agencies to assess the financial performance and operating results of our ongoing business operations. Additionally, we believe adjusted EBITDA provides useful information to investors for trending, analyzing and benchmarking our operating results from period to period as compared to other companies that may have different financing and capital structures. We define Adjusted EBITDA as net income adjusted for: (i) provision for income taxes; (ii) net interest and other financial costs; (iii) depreciation and amortization; (iv) income/(loss) from equity method investments; (v) distributions and adjustments related to equity method investments; (vi) impairment expense; (vii) noncontrolling interests; and (viii) other adjustments, as applicable.

DCF is a financial performance and liquidity measure used by management and by the board of directors of our general partner as a key component in the determination of cash distributions paid to unitholders. We believe DCF is an important financial measure for unitholders as an indicator of cash return on investment and to evaluate whether the partnership is generating sufficient cash flow to support quarterly distributions. In addition, DCF is commonly used by the investment community because the market value of publicly traded partnerships is based, in part, on DCF and cash distributions paid to unitholders. We define DCF as Adjusted EBITDA adjusted for: (i) deferred revenue impacts; (ii) sales-type lease payments, net of income; (iii) adjusted net interest and other financial costs; (iv) net maintenance capital

expenditures; (v) equity method investment capital expenditures paid out; and (vi) other adjustments as deemed necessary.

Adjusted FCF and Adjusted FCF after distributions are financial liquidity measures used by management in the allocation of capital and to assess financial performance. We believe that unitholders may use this metric to analyze our ability to manage leverage and return capital. We define Adjusted FCF as net cash provided by operating activities adjusted for: (i) net cash used in investing activities; (ii) cash contributions from MPC; and (iii) cash distributions to noncontrolling interests. We define Adjusted FCF after distributions as Adjusted FCF less base distributions to common and preferred unitholders. We believe that the presentation of Adjusted EBITDA, DCF, Adjusted FCF and Adjusted FCF after distributions provides useful information to investors in assessing our financial condition and results of operations.

Leverage ratio is a liquidity measure used by management, industry analysts, investors, lenders and rating agencies to analyze our ability to incur and service debt and fund capital expenditures.

The GAAP measures most directly comparable to Adjusted EBITDA and DCF are net income and net cash provided by operating activities while the GAAP measure most directly comparable to Adjusted FCF and Adjusted FCF after distributions is net cash provided by operating activities. These non-GAAP financial measures should not be considered alternatives to GAAP net income or net cash provided by operating activities as they have important limitations as analytical tools because they exclude some but not all items that affect net income and net cash provided by operating activities or any other measure of financial performance or liquidity presented in accordance with GAAP. These non-GAAP financial measures should not be considered in isolation or as substitutes for analysis of our results as reported under GAAP. Additionally, because non-GAAP financial measures may be defined differently by other companies in our industry, our definitions may not be comparable to similarly titled measures of other companies, thereby diminishing their utility.

For a reconciliation of Adjusted EBITDA, DCF, Adjusted FCF, Adjusted FCF after distributions and our leverage ratio to their most directly comparable measures calculated and presented in accordance with GAAP, see the tables below.

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") goals and targets, including those related to greenhouse gas emissions, biodiversity, diversity, equity and inclusion and ESG reporting. Forward-looking and other statements regarding our ESG goals and targets 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 “anticipate,” “believe,” “commitment,” “could,” “design,” “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,” “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, including changes in governmental policies relating to

refined petroleum products, crude oil, natural gas, natural gas liquids (“NGLs”) or renewables, or taxation; 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, inflation or rising interest rates; 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 renewables; 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 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 goals and targets 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 or minimum inventory requirements on companies operating in the energy industry 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, 2023, 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.