How Much of My Classroom Expenses Can I Write Off as a Teacher?

If you work full-time as a teacher, you most likely qualify for the deduction. However, with the tax code you always need to make sure you meet the specific criteria. For the educator expenses deduction, you have to been a teacher, counselor or principal in a school that teaches children in grades kindergarten through grade 12. You must also have worked for at least 900 hours during the year. If you work as a college professor or a preschool teacher, you don't qualify.

Only costs that would be deductible as a trade or business expense can be included in the deduction, such as books, educational software or school supplies. You can only deduct up to $250 each year for your qualifying educator expenses. If you're married and filing a joint return, you can deduct up to $500 as a couple. However, each spouse is still limited to $250. For example, if the husband works as a teacher and has $400 of qualifying expenses and the wife is a doctor, the deduction is limited to $250.

If you have expenses in excess of the $250 limit, you can claim them as unreimbursed employee expenses. However, this deduction is not nearly as advantageous because unreimbursed employee expenses are a miscellaneous deduction, which means you can only deduct the amount of expenses that exceed 2 percent of your adjusted gross income. For example, if your AGI is $40,000, you have $1,000 of teacher expenses (not including the $250 you already claimed), you would only be able to claim a $200 deduction, because 2 percent of your AGI is $800.

The educator expense deduction is claimed on form 1040 as an adjustment to income, so you don't have to decide whether to itemize. The unreimbursed employee expense deduction is an itemized deduction, however, so it must be reported on Schedule A on line 21. After you've calculate the amount in excess of the 2 percent floor, the total deduction is copied to line 27 of Schedule A.