Tribal Business Access to PPP Act This bill modifies the Paycheck Protection Program, established to support small businesses in response to COVID-19 (i.e., coronavirus disease 2019), by waiving affiliation rules that prevent certain tribal business concerns from being eligible to participate in the program. Affiliation rules govern which business entities are counted for the purpose of determining the size of a business, and affiliation occurs when multiple separate businesses are aggregated under one employer identification number and their employees or revenues are combined and counted together.