Since this reimbursement was not included on your W-2 you probably have an "Accountable Plan". In this case, you do not need to report any of the reimbursements as income.
Employers reimburse employees in one of two ways.
Accountable Plan: Must meet three requirements:
1. You must have paid or incurred expenses that are deductible while performing services as an employee.
2. You must adequately account to your employer for these expenses within a reasonable time period, and
3. You must return any excess reimbursement or allowance within a reasonable time period.
Non-Accountable Plan:
The payments you receive should be included in the wages shown on your Form W-2. You must report the income and itemize your deductions to deduct these expenses.
Generally, you would report these expenses on form 2106 or 2106-EZ.
