Federal income tax rules apply to all U.S. citizens, regardless of where they live. A U.S. citizen includes anyone born in the United States, anyone born to a U.S. citizen parent, anyone naturalized, and anyone born in Puerto Rico, Guam, or the U.S. Virgin Islands. Individuals born in American Samoa or the Northern Mariana Islands are U.S. nationals, not citizens, but still fall under special rules.
For this section, the focus is on citizens who must report income from worldwide sources.
Tests for Claiming Dependents
A taxpayer may claim a dependent only if all three of the following tests are met:
- Dependent Taxpayer Test — The taxpayer cannot be the dependent of another person.
- Joint Return Test — A married person filing a joint return cannot be claimed unless the return is filed solely for a refund.
- Citizenship or Resident Test — The dependent must be a U.S. citizen, U.S. resident alien, U.S. national, or a resident of Canada or Mexico for part of the year.
A dependent must also be either a qualifying child or a qualifying relative.
Qualifying Child Tests
A qualifying child must meet all four of the following:
- Relationship Test
The child must be the taxpayer’s child, stepchild, sibling, stepsibling, or a descendant of any of them.
- Age Test
The child must be younger than the taxpayer and:
- Under age 19, or
- Under age 24 and a full‑time student, or
- Any age if permanently and totally disabled
- Residency Test
The child must live with the taxpayer for more than half the year. Temporary absences—such as illness, school, military service, or vacation—count as time lived with the taxpayer.
A child born or who dies during the year qualifies if the home was the child’s home for the entire time alive.
- Support Test
The child cannot provide more than half of their own support.
Tie‑Breaker Rule
If a child meets the qualifying child tests for more than one person, only the person entitled under the tie‑breaker rules may claim the child. For divorced or separated parents, the custodial parent generally has priority unless they release the claim using Form 8332.
Full‑Time Student Definition
A full‑time student is enrolled full‑time for any part of five calendar months. Online‑only schools and correspondence courses do not qualify.
Qualifying Relative Tests
A qualifying relative can be any age. All four tests must be met:
- Not a Qualifying Child Test
The person cannot be a qualifying child of any taxpayer.
- Support Test
The taxpayer must provide more than half of the person’s total support.
- Gross Income Test
The person’s gross income must be less than $5,200 for 2025.
- Member of Household or Relationship Test
The person must either:
- Live with the taxpayer all year, or
- Be related in one of the allowed ways (child, sibling, parent, grandparent, in‑laws, etc.)
Relationships created by marriage do not end due to death or divorce.
A qualifying relative who meets the relationship test does not need to live with the taxpayer. A qualifying relative who meets the household test does not need to be related.
Determining Support
Support includes food, lodging, clothing, education, medical care, recreation, and transportation. To determine whether the taxpayer provided more than half of someone’s support:
- Calculate the person’s total support from all sources.
- Compare the taxpayer’s contribution to that total.
- The person’s own funds count only if actually spent on support.
Multiple Support Agreements
If multiple people together provide more than half of someone’s support, they may agree that one person claims the dependent.
Requirements:
- The claimant must provide more than 10% of total support.
- Each other contributor providing more than 10% must sign a statement agreeing not to claim the dependent.
- The claimant files Form 2120 with their return.