Room and board are not qualified expenses for the AOC. They are qualified expenses for the 1099-Q (529 or ESA distribution).
So, you're doing it backwards. You enter the 1098-T on your return and use $4000 of the box 1 amount to claim the AOC.
You enter the room and board on his TurboTax return, as well as the 1098-T and any book and computers expenses. When you get to the screen* titled “Amount Used to Calculate Education Deduction or Credit”, verify that the amount used is $4000 or change it to $4000 (this prevents the double-counting of expenses).
*If TT doesn't give you that screen, Go through the entire education interview until you reach a screen titled "Your Education Expenses Summary". Click edit next to the student's name. That should take you to a screen “Here’s your Education Summary”. Click edit next to “Education Information”. When you get to the screen titled “Amount Used to Calculate Education Deduction or Credit”, verify the amount you want to use or change it.
@twoods1958
