Idaho State Tax Commission

Idaho State Tax Commission

Tax Reform

Page last updated 04-03-2018

Changes for 2018 Idaho income tax returns

The final 2018 income tax reform bill became law on March 28. Some taxpayers will see a decrease in the tax they owe for 2018, and others will see an increase. We're working on the calculations to update the income tax withholding tables. We'll provide more guidance to taxpayers in a few weeks on how the change will affect their withholding and the tax they owe. Stay tuned to this webpage. If you have a specific tax question, please email us at

Changes for 2017 Idaho income tax returns

Idaho recently passed two laws (House Bill 355, House Bill 624) to follow part of the Internal Revenue Code for tax year 2017. For your 2017 Idaho income tax return:

  • If you itemize:
    • You can claim medical expenses that are higher than 7.5% of your adjusted gross income. (The rate was previously 10%.)
    • You can claim mortgage insurance premiums treated as qualified residence insurance.
  • If you lose your principal residence due to a foreclosure, you don't have to include any forgiven debt in your taxable income.
  • You can claim a deduction for qualified tuition and related expenses. (On Form 40, it's included in your federal adjusted gross income. On Form 43, report on line 22.)
  • You must report and pay tax on the repatriation of previously unreported overseas earnings that could apply to 2017. If you file on a water's-edge basis, attach your IRC 965 Transition Tax Statement to your Idaho return.

See the Conformity page for the full list of federal tax breaks extended by Idaho law.

If you already filed your 2017 taxes, check to see if you need to amend your return. If you e-filed, your software package may support e-filing an amended return.

Page last updated April 3, 2018. Last full review of page: April 3, 2018.

The information on this site is for general guidance only. Tax laws are complex and change regularly. We can't cover every circumstance in our website guides. We work to provide current and accurate information on our website. But some information could have technical inaccuracies or typographical errors. If there's a conflict between current tax law and the information on our website, current tax law will govern.