Protecting Mushroom Farmers Act This bill requires the federal crop insurance program (FCIP) to provide for the research and development of a policy to insure the production of mushrooms and mushroom-growing media. (The term policy means an insurance policy, plan of insurance, provision of a policy or plan of insurance, and related materials.) The Federal Crop Insurance Corporation, the agency that finances FCIP operations, must make any resulting policy available that meets specified FCIP requirements. As part of the research and development, the bill requires an evaluation of the effectiveness of insurance for the production of mushrooms, including policies that (1) are based on the risk of specific pests and pathogens, (2) consider appropriate best practices to minimize the risk of loss, and (3) consider whether to provide coverage for mushrooms under one policy or to provide coverage for various phases of production.