You can claim your child if he is full time student and meet all requirements listed under Qualifying child.
Qualifying child:
- They're related to you.
- They aren't claimed as a dependent by someone else.
- They're a US citizen, resident alien, national, or a Canadian or Mexican resident.
- They aren’t filing a joint return with their spouse.
- They're under the age of 19 (or 24 for full-time students).
- There's no age limit for permanently and totally disabled children.
- They lived with you for more than half the year (exceptions apply).
- They didn't provide more than half of their own support for the year.