Yes, your son can claim an education credit (or deduction) based on the qualified expenses, you paid. Although the general rule, in taxes, is that you must pay it to claim it, education is an exception. All that is necessary is that he was the student (and not somebody's dependent). He did not have to make the payment.
However, he can not claim the more generous American Opportunity Credit (AOC). There is a 4 time limit and all 4 times were used on your returns. He may claim the Lifetime Learning Credit (LLC) or Tuition and Fees Deduction (TFD). TurboTax (TT) will determine which is better (almost always the LLC). The LLC is a maximum of $2000 ($11,503 makes him eligible for the max). But, no part is refundable. It can only reduce his actual tax liability.
