After your child grows up and goes off to school -- even graduate school -- you may still be able to claim an exemption for her on your taxes. To do this, you must prove she meets the IRS definition for either a qualifying child or a qualifying relative.
Full-Time Student
You can still claim your child -- or step-child, adoptive child, foster child or younger sibling -- as a qualifying child after the age of 19, if she's a full-time college student. The IRS defines a full-time student as one who attends college full-time for at least five months of the year, provided it's a school with a regular teaching staff and a student body. The rules specifically exclude Internet colleges and correspondence courses.
Where and How Much
Normally you can only claim a qualifying child if he lives with you at least half the year. The IRS makes several exceptions, one of which is if your child is away at school for part of the year; if she's permanently moved out, however, you're out of luck. To claim your grad student, you have to pay half her support during the year. This includes not only the checks you write for tuition and books, but the value of room and board when she's back home, even if you don't bill her for them.
Qualifying Relative
If your child does move away from home, you can still possibly claim her as a "qualifying relative." A qualifying relative is either a family member who lives with you year-round or one who lives outside your home with your financial support. As of 2012, your daughter can qualify if her legal residence is away at school, provided she earns less than $3,700 a year and you provide more than half her support.
Restrictions
If anyone else, such as an ex-spouse, claims your child as a dependent, you're out of luck: only one person can claim any single dependent. The IRS has a list of guidelines for figuring out which spouse has the stronger claim to take the exemption. If your child gets married and files jointly, you can't claim her as a dependent unless she and her spouse have no tax liability and only filed to get a refund or a tax credit.
