A dependent is someone who relies on another person for financial support, such as for housing, food, clothing, necessities, and more. For tax purposes, a dependent is someone “other than the taxpayer or spouse” who qualifies to be claimed by someone else on a tax return. Dependents can be either a qualifying child or a qualifying relative. A qualifying child can be a biological child, stepchild, foster child, sibling, step-sibling, or a descendant of any of these individuals, provided they are less than 19 years old (or 24 if a full-time student) for the entire tax year and meet other requirements. A qualifying relative could include parents, stepparents, grandparents, nieces, and other relatives who are eligible, assuming you provide more than half of their financial support. To be claimed as a dependent, a person must be a U.S. citizen, U.S. resident alien, U.S. national, or a resident of Canada or Mexico.