You can do it either way: file the amount on 1098-T this year and show the repayment from your employer next year (since you deducted it the year before). Check with your employer to see if he/she is going to send you a 1099-MISC next year (or add it to your W-2) for the reimbursed tuition. If your employer is NOT going to give you a statement showing the tuition as a reimbursement, then you don't need to worry about it. Make SURE the reimbursement is NOT going to be counted as "other income" from your employer next year before you ignore the 1098-T for 2019.
