A turbotax associate just helped me thru this exact question. For me, the undergraduate box was pre-populated, but greyed out so that I couldn't delete it. Go ahead and enter that same interest value in the graduate box, click continue to the next screen, and it should delete the undergraduate portion automatically for you. There wasn't an actual question to specify graduate vs. undergraduate; you just enter the value and let the system populate for you. Depending on your state it does matter which you choose. For me, if it was undergraduate I would have received a credit, but graduate did not receive any credit amount. Hope this helps.