Dependent Income Exclusion Act of 2021 This bill excludes certain wages or self-employment earnings of a dependent of a taxpayer for purposes of determining the taxpayer's eligibility for premium tax credits used to purchase insurance on Patient Protection and Affordable Care Act exchanges. To qualify for the exclusion, the dependent must be under 18 years of age or have not attained age 24 during a specified five-year period, and be a full- or part-time student or apprentice or participant in a job training program.