My daughter is a college freshman and had $6950 of QEE (tuition, fees, required books) for the fall 2017 semester, with additional expenses of $5938 for room and board. She received $9525 in scholarships. I am claiming her as a dependent on our return. In going through the questions on TT, I specified to use $4000 of her QEE to generate the AOC credit of $2500. However, it seems that TT only used $3816 of QEE to generate an AOC credit of $2454. Our AGI is below the $160K threshold for MFJ, so we should be eligible for the full $2500 AOC. The discrepancy is small I know, but I'm curious why TT deviated from what I requested (full $4000). Is TT doing some kind of behind the scenes optimization here?