if employer reimbursed part of tuition stated on 1098-T, is this considered "already listed" on a tax form? Or can I put the amount that I was reimbursed when prompted?

Did they include the reimbursement on your W-2?  If they did, then it was already listed on a tax form.  Also, if the amount that they reimbursed for books and fees not on the 1098-T were included on your W-2, then you would enter these expenses when prompted as well. 

If it was not included on your W-2, then you would enter the amount you were reimbursed when prompted.  Also, if it was NOT included on your W-2, you can enter the expenses when prompted and then include the ENTIRE amount you were reimbursed in the question for reimbursement. 

 

Q. Should  I put the amount that I was reimbursed when prompted?

A. You put the tax free amount that they reimbursed. 

By law your employer can only give you $5250 maximum, tax free. If your tuition and books was less than that, and you employer reimbursed it all; it’s  safe to assume it does not need to be reported. You do not even need to enter your 1098-T. You have nothing to claim.

 If you got more than $5250, the amount above $5250 is usually already included in box 1 of  your w-2.  Since you have essentially paid tax on that part, it  is considered your after tax money and that amount can be used  to claim the tuition credit.

In TurboTax, you would enter the $5250 when prompted for the amount of employer reimbursement.