The previous discussion on this thread is essentially "off track". There is no exclusion, from taxation, of employer reimbursement for work related tuition. Employers are allowed to set up a qualified tuition reimbursement plan for any education (graduate, undergraduate or trade school; work related or not work related) at eligible institutions. The first $5250 is tax free and is not to be included in box 1 of the employee's W-2. Your employer's plan must meet IRS regulations.
Bottom line: there is no way to file your tax return to "undo" what your employer reports on your W-2. If your employer reported the reimbursement as income, then it is taxable income. If he made a mistake, a corrected W-2 is the only remedy.
If the education was work related, the employee was allowed (prior to 2018) to claim an itemized deduction, subject to the 2% of AGI rule. But starting in 2018, job expenses, including education, are no longer deductible. The $5250 tax free tuition reimbursement is still allowed.
