CALIFORNIA TRANSPARENCY IN SUPPLY CHAINS ACT DISCLOSURE (SB 657)

The California Transparency in Supply Chains Act of 2010 (SB 657) requires companies that manufacture or sell products in the State of California to disclose their efforts, if any, to eradicate slavery and human trafficking in their direct supply chains. The law was designed to increase consumers' knowledge about products they buy and the companies they choose to support.

Marathon Petroleum Corporation, its subsidiaries and affiliates (“MPC”) are committed to complying with the law wherever we operate and conducting all business activities in accordance with the highest ethical standards. We expect the same of the parties with which we do business. Our ethical standard is reflected in our Code of Business Conduct, which outlines our expectations of ethical conduct and compliance with all laws from our employees and others who work and represent MPC. In addition to receiving our Code, members of our Board of Directors, executive officers and salaried employees take ethics and compliance training and certify their adherence with the Code's standards, or disclose any exceptions. MPC maintains a 24/7 Business Conduct Helpline where employees and contractors can submit, anonymously, if requested, any concerns of possible ethics and compliance violations, including slavery and human trafficking. Every submission is reviewed and addressed. Any employee or contractor who is found to have violated the Code provision is subject to disciplinary action, up to and including termination of employment or contracts, and referral to proper legal authorities.

To ensure that our supply chain reflects our commitment to compliance and ethics standards, our corporate business practice provides that MPC's purchasing decisions with suppliers are based on integrity. MPC expects its suppliers to follow legal requirements and operate consistently with the principles of our Code of Business Conduct when working on our behalf. MPC also has a stand‐alone Supplier Code of Conduct that further emphasizes our expectations in the areas of legal and ethical compliance, environmental, health, safety and security, conflict minerals, conflicts of interest, human rights, diversity, compliance assurance and reporting. Accordingly, we consider human rights issues when we assess potential suppliers. Suppliers are encouraged to report, anonymously if requested, unethical or illegal acts, or suspicions of unethical or illegal acts via MPC's Integrity Helpline. Suppliers that do not comply with our Code of Business Conduct or Supplier Code of Conduct will be subject to appropriate sanctions, including the possible cancellation of all current and future contracts.

While MPC does not have a formal verification or certification program, we do perform periodic internal audits of suppliers to evaluate and address issues relating to compliance with regulations and MPC's policies, processes, and procedures. At this time, MPC's audits of its suppliers are not independent or unannounced.