To be claimed as your dependent, an individual must meet five tests:
Gross income test. In 2018, the gross income test is met if the potential dependent has gross income of $4,150 or less. If the dependent is your child, there is no income limit as long as the child is under age 19. If the child is a full-time student for at least five months out of the year, there is no income limit until age 24. Tax-exempt income, such as nontaxable social security benefits, is not included as gross income for purposes of this test.
Member of household or relationship test. The dependent must either live in your home or be closely related.
Citizenship test. The dependent must be a resident of the U.S., Canada, or Mexico, or be a US citizen or national.
Joint return test. The dependent, if married, cannot file a joint return with his or her spouse, unless a joint return is filed just to get a refund for withheld taxes.
Support test. You must pay more than 50% of the dependent's expenses for the year or qualify to claim the dependent under a multiple support agreement. Support generally includes all funds that were actually spent during the year.
Planning will enable you to maximize your dependency deductions. If your status is changing due to marriage, divorce, adoption or new birth you may need a review of your situation.