Sending Unconditional Payments to People Overcoming Resistances to Triumph Act of 2021 or the SUPPORT Act of 2021 This bill establishes a guaranteed income pilot program and tax credit and provides for bank accounts supported by Federal Reserve banks. The bill establishes the Office of Guaranteed Income Programs to carry out a five-year guaranteed income pilot program. The pilot program must provide grants through local governments and community development financial institutions for periodic cash payments to eligible individuals. An eligible program must provide cash payments that are not less than $50 per individual and are made on a biweekly, monthly, or quarterly basis. Additionally, the bill establishes the Guaranteed Income Tax Credit, a refundable income tax credit for individual taxpayers equal to $14,400 plus $600 for each dependent. The amount is reduced for individuals whose adjusted gross income exceeds specified levels. A taxpayer may elect to receive this credit in advance in equal amounts throughout the year. The bill also requires Federal Reserve member banks to provide bank accounts ( FedAccounts ) to residents and to businesses domiciled in the United States for purposes of holding digital dollar balances. These accounts must provide specified banking services, including debit cards, online banking, automatic bill pay, and automatic teller machines at U.S. postal facilities. These accounts may not charge fees or have balance requirements and must provide a specified interest rate.