This page has been updated for 2018 taxes and may not apply to previous years.
As a result of the Tax Cuts and Jobs Act of 2017 (2017 tax reform): a deduction for unreimbursed employee expenses will be eliminated for individuals from 2018 through 2025. Instead check to see if your employer can reimburse you for your expenses. Reimbursed expenses under an accountable plan are excluded from your taxable income even though they are reported on your W-2 line 12.
Businesses, however, will be able to claim a deduction for employee reimbursements -- provided that the expenses are legitimate business expenses and the reimbursements comply with IRS rules. If you have a business with qualified expenses, you would report those expenses directly on your Schedule C.