There are four tests to determine if your child can be claimed as a dependent on your tax return: relationship test, member of the household test, age test, and support test. In most cases, you are able to claim the child as a dependent if they are under age 19 and you provide more than 50% of their support OR if they are a full-time student under age 24, you most likely will be able to claim that child. This area can get very complex, so you should check with a tax professional before making a final decision.