2020 ANNUAL REPORT Table of Contents President and CEO Letter 1 Operations Overview 4 Core Values 6 Financial Highlights 7 Sustainability 8 - Social Responsibility 8 - Leading in Sustainable Energy 9 - Safety and Environmental Stewardship 11 Board of Directors 12 Executive Team 13 On the cover: Our Dickinson, North Dakota, plant undergoing conversion to a renewable diesel facility. Construction was completed and production began in late 2020. FROM THE PRESIDENT AND CEO Fellow Shareholders, 2020 was a pivotal year for Marathon as we began a process to transform the company, lowering our cost structure and shaping our asset portfolio amid evolving stakeholder expectations and opportunities created by the energy evolution. While these efforts continue through 2021, we made significant progress during the year. Despite the demands of COVID-19, our teams remained focused on our core values and on their central mission. As a result, we set a new industry benchmark for certifications in the EPA’s ENERGY STAR ® program and achieved significant improvements over 2019 in our process safety and environmental performance. Complemented by our ongoing sustainability focus, which inspired us to take industry-leading actions, our efforts collectively served to enhance the company’s competitiveness and longevity amid shifting market dynamics. Our humanitarian and operational responses to the COVID-19 pandemic reflected our broader vision of sustainability, which emphasizes delivering essential energy products and services to the world in ways that create shared value for all our stakeholders – our people, business partners, customers, communities, governments and shareholders. We deployed more than 500,000 N95 respirator masks to frontline healthcare workers in our local communities and increased our employee giving match from 60% to 100%. The Marathon Petroleum Foundation also donated $1 million to the American Red Cross to supply critical resources. Building Resiliency – Our Strategic Initiatives We quickly began implementing actions to strengthen the competitive position of our assets, improve our commercial performance and lower our cost structure. We made significant moves in our portfolio in 2020, which included: • Reaching an agreement with 7-Eleven for the pending sale of our Speedway retail business for $21 billion, which will help strengthen our balance sheet and return capital to MPC shareholders. • Beginning production at our Dickinson, North Dakota, renewable diesel facility, which is the second largest facility of its kind in the United States, designed to produce approximately 180 million gallons per year. This facility is anticipated to reach its full rate of production by the end of the first quarter of 2021. • Moving forward with engineering and permitting efforts on a project to convert our idled Martinez, California, refinery to a facility that produces renewable transportation fuels. It is anticipated this project would be commissioned in 2022 and eventually reach a production capacity of approximately 730 million gallons per year. MARATHON PETROLEUM CORPORATION I 2020 ANNUAL REPORT I 1 FROM THE PRESIDENT AND CEO • Advancing several midstream projects that support the goal of developing long-haul pipelines, including the Wink to Webster crude oil pipeline, the Whistler natural gas pipeline and the reversal of the Capline crude pipeline. • Invested to expand our natural gas processing and fractionation assets in the Marcellus and Permian basins, our long-term strategic focus areas. • Divested or announced plans to divest less strategic assets such as the Javelina processing facility and several asphalt terminals. To improve our commercial performance: • We are leveraging our proximity to key supply sources and demand hubs, so we can capture higher margins across the value chain. • We aim to maximize value by enhancing raw material selection in our refining segment and improving product placement. • In midstream, we are working to grow our fee-based services through long-term contracts to provide through-cycle cash flow stability. In 2020, our midstream segment, which includes MPLX, earned $3.7 billion in income from operations, a $113 million increase from the year before. To lower our overall cost structure, our 2020 initiatives included: • Indefinitely idling two higher-cost refineries and advancing plans to convert one of them to renewable fuel production. • Reducing our capital spending levels by more than $1.4 billion from our initial plans for MPC and MPLX. • Reducing our refining operating expenses by more than $1 billion and our midstream operating expenses by more than $200 million. • Applying strict cost management practices to reduce our overall corporate costs. Additionally, our 2021 capital spending outlook, excluding MPLX, is approximately $350 million less than 2020’s total. Sustainability - Focused on the Future The goals of our strategic initiatives complement and further enable our commitment to sustainability, which spans the environmental, social and governance (ESG) dimensions of our operations. In 2020, we strengthened our efforts to lower our carbon intensity and produce a range of fuels that meet the needs of evolving and emerging consumer demands, consistent with our principles for Leading in Sustainable Energy. These principles correspond with several of our most substantial 2020 achievements: 2 • Becoming the first independent U.S. refiner to create a company- wide goal for reducing greenhouse gas emissions intensity and link it to employee and executive compensation. • Becoming the first-ever petroleum refiner to have five refineries earn ENERGY STAR® certifications in one year. • Establishing a program to lower methane emissions at our natural gas gathering and processing assets that included an intensity reduction target, as well as becoming one of the first companies to launch a program to track and reduce freshwater withdrawal intensity across all our refineries. We made a significant shift and have designated $350 million in capital spending for renewable projects in 2021, representing 25% of our capital budget, excluding MPLX, and a substantial portion of our incremental growth capital for the year. In 2020, we also had several accomplishments in the areas of social and governance, including a new Human Rights Policy incorporated in our sustainability reporting, increased participation in our Diversity & Inclusion programs, comprehensive stakeholder engagement plans for all major assets and sustainability performance linked to compen- sation. These efforts contributed to MPC earning high scores from ESG rating organizations that are monitored by institutional investment firms. Our scores led to several recognitions, such as placement on the Dow Jones Sustainability Index and the Forbes JUST 100. Our comprehensive sustainability framework helps to differentiate us and provides us with the flexibility to accommodate a variety of emerging topics and marketplace demands. As we look ahead in 2021, the availability of COVID-19 vaccines provides hope for the return of global transportation fuel demand and economic recovery. Even though many uncertainties still exist, the world’s need for reliable, affordable and responsibly produced energy remains important. We believe we can continue to meet this need through our strategies that will allow us to successfully adapt to the evolving energy landscape. Sincerely, Michael J. Hennigan President and Chief Executive Officer MARATHON PETROLEUM CORPORATION I 2020 ANNUAL REPORT I 3 OPERATIONS OVERVIEW Standard cubic feet per day of 2.9 11.8 natural gas million billion processing capacity Barrels per calendar day of crude oil refining capacity 4 MPC Refinery MPC Owned Light Product Terminal MPC Owned Asphalt/ Heavy Oil Terminal MPC Owned and Part-Owned Marine Facility MPC/MPLX Pipeline (a) Cavern MPC Domestic Marketing Area (d) MPC International Marketing Area Ethanol Facility MPC Biodiesel Facility Virent (c) MPC Renewable Diesel Facility Martinez Renewable Fuels Project (a) Includes MPC/MPLX owned and operated lines, MPC/ MPLX Owned and Part-Owned MPLX interest lines operated by others and MPC/MPLX Light Product Terminal operated lines owned by others. (b) Includes MPLX owned and operated natural gas MPLX Owned Asphalt/Heavy Oil processing complexes. Terminal (c) Wholly owned subsidiary of MPC working to commercialize MPLX Natural Gas Processing the conversion of biobased feedstocks into renewable Complex (b) fuels and chemicals. Illustrative representation of asset map (d) Area subject to change following the pending sale of MPLX Refining Logistics Asset as of Dec. 31, 2020. Speedway. MPLX Gathering System MPLX Owned Marine Facility 112 ~12,000 Owned and operated North American Retail & Marketing light product and asphalt * terminals locations * We expect to sell Speedway, which represents 3,839 locations. MARATHON PETROLEUM CORPORATION I 2020 ANNUAL REPORT I 5 CORE VALUES Our values guide the way we treat each other and all our stakeholders. We believe our behaviors are just as important as what we do. Safety and Environmental Stewardship Protecting our people and the world we all share is a priority to MPC. We are committed to safe and environmentally responsible Safety and operations to protect the health and safety of our employees, Environmental Stewardship contractors and communities. This commitment is reflected in our safety systems design, our well-maintained equipment and our focus on continuous learning and improvement. Integrity Integrity