Dependent Income Exclusion Act of 2021 This bill excludes the wages and net earnings from self-employment of a dependent of a taxpayer from the calculation of total household income for purposes of determining eligibility for and the amount of the refundable premium tax credit, subject to limitations. Under current law, eligible taxpayers may be able to claim the premium tax credit, which applies toward the cost of obtaining health insurance through health insurance exchanges. To be eligible for the credit, a taxpayer’s household income must meet or exceed 100% of the federal poverty level (FPL). For tax years before 2021 and after 2022, taxpayers must have a household income that meets or exceeds 100% but is less than 400% of the FPL to be eligible for the tax credit. Further, under current law, the calculation of the premium tax credit is based, in part, on taxpayers’ household income such that taxpayers with lower household incomes are eligible for a higher premium tax credit. The bill excludes from household income the wages and net earnings from self-employment of a dependent of the taxpayer who (1) is under 18 years old; or (2) is under 24 years old and is, during any five calendar months of the year, a full- or part-time student in an educational organization (excluding for-profit educational institutions), is in an apprentice program, or is participating in a job training program. The amount that may be excluded is limited to 15% of the taxpayer’s modified adjusted gross income.