You need to enter the qualified education expenses that were paid for his education. He should have received a Form 1098-T for those expenses which you enter on your tax return since he is being claimed as your dependent.
To enter, edit or delete Education Expenses -
Click on Federal Taxes (Personal using Home and Business)
Click on Deductions and Credits
Click on I'll choose what I work on (if shown)
Scroll down to Education
On Expenses and Scholarships (Form 1098-T), click on the start or update button
Or enter education expenses in the Search box located in the upper right of the program screen. Click on Jump to education expenses
