If you pay more than 50% of students support, he is still a dependent. Unfortunately when student gets full tuition and room and board, it's hard to justify an amount equal or greater to that number.
This is true. Those with dependency questions should refer to IRS publication 501. There are 5 conditions that all must be met to claim someone as a dependent:
Relationship
Age
Residency
Support
Joint Return
The 'support' condition trips folks up lots of time. Basically, you must have provided for over 50% of your childs *support*. Tuition, room and board away at school all count as *support*. For instance, if they are getting $40,000/year in scholarships, grants etc; then you have to show you are providing $40,001 in additional support through out the year. Perhaps buying your 20 year old a beemer would count.
This is HIGHLY individual and will vary from family to family.
One other thing - be wary of 1098T's provided by the college. After 14 kid college years and looking at 14 1098T's from 5 different colleges; I can tell you they are often not correct.
Keep your own records and spreadsheets. Again this is going to vary by circumstance. To avoid being taxed on scholarships apply them to tuition first. However in order to claim the American Opportunity Credit (if you qualify by income) you need to apply loans or cash to the tuition. You can't take the credit, which is for tuition, books only (not room and board) if the scholarship covers the tuition.
Here's where it gets tricky - if the scholarship is designation to tuition then you can't claim the AEO for those costs. But if you get a grant from the college that is applied to the bill - you can target that toward room and board and any loans/cash to the tuition in your own record keeping.
Each year I keep a spreadsheet with the college costs and how they are paid - scholarship/grant, loans, cash. This trumps the 1098T.
Finally (just one more point!) - in MOST cases the college will not award you more that the Cost of Attendance. The idea of 'making money' off college does not really work if you are receiving financial aid.