Advanced Technology Vehicles Manufacturing Future Act of 2021 or the ATVM Future Act This bill reauthorizes through FY2031 and revises the Advanced Technology Vehicles Manufacturing Loan Program within the Department of Energy (DOE). Under the existing program, DOE provides financial support for the production of advanced technology vehicles. The bill expands the program to include financial support for (1) medium-duty passenger vehicles and heavy-duty vehicles that meet specified emission standards or emit zero-emissions; and (2) components, such as batteries, of ultra-efficient vehicles. The bill also revises the emission standards that light-duty vehicles must meet to be eligible for assistance under the program. In addition, the bill revises requirements governing the evaluation of a loan applicant's prospects of repaying a loan under the program.