Individual Filing Requirements

For Tax Years Beginning After December 31, 2023

In general, if during the tax year you were a resident or part-year resident of Montana, or if you were a nonresident who received Montana source income; and you had a requirement to file a federal tax return, then you must file a Montana income tax return. If you did not have a federal filing requirement, but have a Montana addition or subtraction, you also must file a Montana income tax return.

Important: If you qualify for the federal Earned Income Tax Credit, you may qualify for the Montana Earned Income Tax Credit. However, you must file a Montana income tax return to claim the credit.

Additionally, if you qualify for the Elderly Homeowner/Renter Credit, you must file a Montana tax return to claim the credit.

You should file a return if you had Montana tax withheld from your paycheck or if you paid estimated income tax, even if you aren't required to file a return.

Filing a return is the only way to get your refund.

Enrolled Member of a Tribe

Generally, if you are an enrolled member of a tribe and you live on the reservation governed by your tribe, you have a Montana filing requirement. However, you can subtract the income that can be sourced to the reservation governed by your tribe. Learn more about Montana Income Taxes for Enrolled Tribal Members.

Filing Requirement for Taxpayers with Losses

If you incurred or reported losses (including capital losses, passive losses, and net operating losses), you must file a Montana tax return to track the sourcing of the losses and to use those losses in calculating your tax liability. Unreported losses may lead to the disallowance of their use in future years.

Calculating Your Montana Taxes (Tax Year 2024 and Later)

Beginning with tax year 2024, under Senate Bill 399 (2021), the calculation of Montana tax will change. More information about this change is available on the Montana Tax Simplification Resource Hub.

  1. Calculate your federal taxable income. 
  2. Add your Montana additions (15-30-2120,MCA)
  3. Subtract your Montana subtractions (15-30-2120,MCA)
  4. You now have your Montana taxable income
  5. Use your Montana taxable income on the Montana Tax Rates Table
  6. Apply your tax rate to your Montana taxable income based on the character of the income (ordinary income or long-term capital gains)
  7. Subtract any tax credits you qualify for in this order: 
    1. Nonrefundable, single-year tax credits you can't carryover
    2. Nonrefundable tax credits you can carryover
    3. Refundable tax credits

Exemptions to the Filing Requirement

There is a filing exclusion for certain nonresidents. Nonresidents who earned only wages for services performed in Montana for 30 days or less and worked in more than one state during the tax year do not have to file a tax return or pay tax to Montana on that income.
Employees Not Eligible for This Exclusion

The exclusion does not apply to the following types of employees: 

  • Professional athletes
  • Entertainers
  • Persons performing services for compensation on a per-event basis
  • Construction workers
  • Employees with annual salaries of more than $500,000
  • Qualified production employees for purposes of the MEDIA Credit
When the Exclusion Does Not Apply

If a nonresident employee worked in Montana for more than 30 days or only worked in Montana, then all income earned while working in the state is taxable to Montana and the employee must follow the general filing requirement. Additionally, this exemption does not apply to nonresident employees who have other Montana source income. For example, a nonresident employee worked in Montana for 15 days. The nonresident also has a rental property located in Montana. This nonresident’s wages and rental income are taxable to Montana.

Self-Employed Taxpayers

This exclusion does not apply to self-employed taxpayers, such as a sole proprietors or owners of pass-through entities, or any other Montana source income.

Filing to Claim Withholding Refund

If your employer withheld Montana taxes from your wages and you are eligible for the exclusion, you must file a Montana income tax return to receive a refund of your withholding.

Generally, if you are a nonresident military servicemember or nonresident spouse of an active duty servicemember and you do not have any other Montana source income, you do not have a filing requirement. Learn more about filing for active duty servicemembers and their spouses.

For Tax Years Beginning Before January 1, 2024

You must file a Montana Individual Income Tax return if:

  • You were a resident or part-year resident of Montana, or
  • You were a nonresident who received Montana source income, and
  • Your federal gross income, excluding unemployment compensation, meets the Montana filing threshold.

You should file a return if you had Montana tax withheld from your paycheck or if you paid estimated income tax, even if you aren't required to file a return.

Filing requirement thresholds are listed in the Form 2 Instruction Booklet of each tax year.

Calculating Your Montana Taxes (Before 2024)

The Montana Individual Income Tax Instruction Booklet has the full instructions for calculating your tax liability, but you can get a rough estimate by following the steps below.

  1. Calculate your Federal Adjusted Gross Income (FAGI)
  2. Add your Montana additions using the Montana Additions Schedule (Form 2, Page 3) (repealed as of January 1, 2024))
  3. Subtract your Montana subtractions using the Montana Subtractions Schedule (Form 2, Page 4) (repealed as of January 1, 2024))
  4. Subtract your deductions, using either your standard deduction (repealed as of 12/31/2023) or the Itemized Deduction Schedule (Form 2, Page 6)
  5. Subtract your total exemptions (repealed as of January 1, 2024)
  6. You now have your Montana taxable income
  7. Use your Montana taxable income on the Montana Tax Rates Table
  8. Apply your tax rate to your Montana taxable income
  9. Subtract any tax credits you qualify for in this order:
    1. 2% capital gains tax credit
    2. Nonrefundable, single-year tax credits you can't carryover
    3. Nonrefundable tax credits you can carryover
    4. Refundable tax credits
Notes on Credits

Nonrefundable tax credits are reported on the Nonrefundable Credits Schedule (Form 2, Page 9). Refundable tax credits are reported on the Other Payments and Refundable Credits Schedule (Form 2, Page 11), with the exception of the Montana Earned Income Credit, which is reported on Form 2, Page 1, line 23b. Most tax credits must be calculated on their own form. A full listing of tax credits and their forms are included in the Montana Individual Income Tax Instruction Booklet.