IRS Link to Form — Found Here

Form 2106 is the long-form way to request deductions for unreimbursed business expenses incurred by an employee in the course of work.

This can include professional affiliation dues, continuing education, insurances, vehicle mileage and depreciation, and other possible deductions.

Often, employees are not reimbursed for every out-of-pocket expense they incur in the course of their work. This might include wear and tear on a vehicle, professional dues, travel expenses, business meals, and many more items. For any amount to go towards a tax deduction, the itemized unreimbursed expenses must be over 2% of adjusted gross income.

Some people are unfamiliar with situations in which an employee would pay out-of-pocket for things related to work, but rest assured that some employees are virtually self-employed when it comes to the amounts that they end up spending out of their own pocket to achieve the goals of the job. The 2106-EZ is the simpler version of this form, but it has fewer options and is not appropriate for very detailed filings.