Capping Costs for Consumers Act of 2021 This bill expands and provides funding for assistance to certain individuals who enroll in plans through health insurance exchanges. Specifically, it increases the premium assistance tax credit by revising, from the second-lowest cost silver plan to the second-lowest cost gold plan, the benchmark plan on which the credit amount is based. The bill also requires individuals to enroll in a gold plan to be eligible for cost-sharing reductions and it extends the reductions to individuals with a higher maximum household income. These changes apply to plan and tax years beginning on or after January 1, 2023.