Do you itemize? If so, your union dues are expenses that you can claim as miscellaneous itemized deductions. These are entered as unreimbursed employee expenses on Line 21 on Schedule A (Form 1040).
Here are the rules, from the 2015 IRS publication:
you can deduct union dues and initiation fees you pay for union membership provided that they and other expenses within the deduction category exceed 2% of your adjusted gross income (AGI).
you can also deduct assessments for benefit payments to unemployed union members.
you cannot deduct the part of the assessments or contributions that provides funds for the payment of sick, accident, or death benefits.
you can't deduct contributions to a pension fund, even if the union requires you to make the contributions.
You are also not able to deduct payments to the Union that are related to certain lobbying and political activities. That means contributions to TEPAC, the Treasury Employees Political Action Committee that seeks to elect pro-labor candidates to office, are not deductible.
You can review the rules for yourself by clicking here.
Contact your CPA or the friendly folks at the IRS (also part of NTEU!) if you have additional questions. Here are the IRS phone numbers:
Thanks to Denise Walker, NTEU Chapter 280 Steward from the Office of General Counsel for putting together this article.