Supermarket Tax Credit for Underserved Areas Act This bill expands the tax credits that are available for the establishment of supermarkets in underserved areas (i.e., any enterprise community or empowerment zone and any renewal community). The bill includes provisions that (1) increase the rate of the rehabilitation tax credit for a supermarket building placed in service after December 31, 2019, and before January 1, 2022, in an underserved area; (2) increase by $1,000 the limit on wages eligible for the work opportunity tax credit for employees of a new supermarket located in an underserved area; and (3) allow a business-related tax credit for 15% of the gross receipts from the retail sale of locally grown fresh fruits and vegetables in a new supermarket in an underserved area.