Introduction
This guide covers income you earn during tax year 2026. You will generally report it on a Montana return filed in 2027. It is not about the 2025 return you file during 2026, which still uses the older 4.7%/5.9% rates.
Montana's 2026 rules look different from last year's. The lower-rate bracket expanded sharply, the top rate dropped, and the Earned Income Tax Credit changed. Some Form 2 mechanics also still rest on the 2025 package.
Below you'll find the new rates, who must file, how Form 2 works, deductions and credits, and deadlines and payment options. Confirm every figure against the Montana Department of Revenue (DOR) before you file.
Key Takeaways
- Montana taxes 2026 ordinary income at two rates, 4.7% and 5.65%, with thresholds that vary by filing status.
- Net long-term capital gains use separate 3% and 4.1% rates, stacked on top of ordinary income.
- The Montana EITC rises to 20% of the federal credit in 2026, so check DOR's current rules.
- Residency, Montana-source income, and the gap between filing and payment deadlines drive a correct return.
What Changed for Montana Individual Income Tax in 2026?
2026 Montana Ordinary-Income Tax Brackets
House Bill 337 rewrote the brackets for 2026 and 2027. The DOR HB 337 summary confirms these figures. They apply to taxable income excluding net long-term gains, not gross income.
| Filing status | 4.7% on first | 5.65% above |
|---|---|---|
| Single / married filing separately | $47,500 | $47,500 |
| Head of household | $71,250 | $71,250 |
| Married filing jointly / qualifying surviving spouse | $95,000 | $95,000 |
For comparison, the 2025 lower-rate breakpoints were $21,100 (single), $31,700 (head of household) and $42,200 (joint). In 2027 the top rate falls again to 5.4%, and the breakpoints rise to $65,000, $97,500 and $130,000. Keep 2027 numbers out of your 2026 math.
Long-Term Capital Gains Treatment
Net long-term gains come out of the ordinary-income calculation and get their own rates:
- 3% applies to gains within the unused part of your status's lower band, after ordinary taxable income fills it.
- 4.1% applies to gains above that band.
- If ordinary taxable income already reaches the breakpoint, all net long-term gains are taxed at 4.1%.
- Long-term means held more than one year. Short-term gains are taxed as ordinary income.
Gains are not automatically taxed at 3%. Form 2 computes gains tax separately from ordinary tax. The 2025 instructions generally use the lesser of federal Schedule D lines 15 and 16. Confirm the matching line references on the 2026 Form 2 instructions when you file.
How HB 337 Affects Taxpayers
The law widens the 4.7% bracket and cuts the upper rate for 2026 and 2027. It doesn't cut everyone's effective rate by the same amount. A single filer with $40,000 of taxable income sits entirely in the 4.7% band under both old and new law, while a filer near $100,000 sees a much larger drop.
Withholding changed too. DOR's 2026 withholding update says new wage tables and a revised MW-4 took effect January 1, 2026. Withholding now uses the federal standard deduction by federal filing status rather than Montana allowances.
Paychecks only cover wages. If you have rental, business, investment or gain income, plan on estimated payments or an additional withholding request.
Filing Status and Taxable Income
Montana generally requires the same filing status as your federal return. Joint federal filers stay joint in Montana, even when spouses have different residency statuses. In that case, use Schedule II. If you owe no federal return, use the status that would apply federally.
The status sets your threshold: single and married filing separately use $47,500, head of household $71,250, and joint or surviving spouse $95,000. NRI and OCI filers follow the same status rules; Montana has not published a separate exception for them.
How Montana Tax Is Calculated
The path runs in order:
- Start with federal taxable income.
- Add Montana additions, such as state income taxes deducted federally (limited by the federal standard deduction).
- Subtract Montana subtractions.
- Split out net long-term gains and compute that tax separately.
- Apply the rates to ordinary taxable income.
- Subtract credits, withholding and estimated payments to reach your balance due or refund.
The federal qualified business income deduction is not allowed in Montana. Schedule I holds adjustments and Schedule III holds credits.
Hypothetical example (illustration only, not personal advice): A single filer has $60,000 of Montana ordinary taxable income and no gains.
- $47,500 × 4.7% = $2,232.50
- $12,500 × 5.65% = $706.25
- Tax before credits: $2,938.75
Now suppose that filer had $40,000 of ordinary taxable income plus $10,000 of net long-term gains. The first $7,500 of gains falls in the unused band at 3% ($225), and the remaining $2,500 is taxed at 4.1% ($102.50).
Who Needs to File a 2026 Montana Individual Income Tax Return?
Full-Year Montana Residents
Residents are taxed on all income, including income from outside Montana. Filing generally depends on your federal filing requirement, Montana income, and any Montana additions, subtractions or credits. A Montana adjustment can require a return even if you owe no federal return.
Part-Year Residents and Nonresidents
| Taxpayer | Income Montana taxes |
|---|---|
| Full-year resident | All income |
| Part-year resident | Income while resident, plus Montana-source income while a nonresident |
| Nonresident | Montana-source income only |
Part-year and nonresident filers allocate income on Schedule II. Schedule IV is not the allocation schedule. Identify your move dates, then separate income by period and source. Nonresidents with Montana wages, business, rental or gain income should check DOR's current sourcing rules.
Federal Versus Montana Filing Requirements
A federal filing obligation is a starting point, not the full answer. Do not assume Montana uses the same dollar thresholds as the IRS. Confirm current thresholds on DOR's filing requirements page and in the 2026 Form 2 instructions.
Income That May Trigger a Return
- Wages and self-employment income
- Pass-through and rental income
- Interest, dividends and capital gains
- Retirement distributions
- Gambling and prize winnings
Special Situations
- Remote and multistate workers: Work done physically in Montana generally creates Montana-source wages. Some nonresident employees in Montana 30 days or fewer may be excluded, unless other Montana income (such as rental income) disqualifies them.
- Business owners: Sole proprietors cannot use the 30-day employee exclusion.
- Dependents: Personal and dependent exemptions were repealed; confirm any 2026 dependent filing threshold in the Form 2 instructions.
- Foreign or cross-border income: Residents are taxed on worldwide income, and the foreign tax credit is limited.
Complex residency, business, or international facts should be checked against the 2026 Form 2 instructions or reviewed with a qualified tax professional.
How to Prepare and File Your Montana Form 2 Return
Gather Documents Before Starting
- Federal return and schedules
- W-2s and 1099s showing Montana withholding
- Retirement and investment statements
- Business and rental schedules
- Prior-year Montana return
- Estimated-payment confirmations
- Records supporting credits and subtractions
Start With the Federal Return and Identify Montana Adjustments
Finalize the federal return first. Form 2 begins with federal figures, then applies Montana additions, subtractions and credits.
DOR's Form 2 page may still show the 2025 package until the 2026 release is posted. Download the 2026 form, instructions and tax tables once DOR publishes them. Don't use a prior-year form for 2026 income.
Choose Electronic or Paper Filing
DOR's filing options page lists approved e-file software, Free File Alliance offers for eligible taxpayers, and paper filing.
- E-file: Software handles identity verification, direct deposit details and confirmation.
- Paper: Send signed pages 1 and 2, applicable Montana schedules, the federal Form 1040 with schedules, and W-2/1099s showing Montana withholding (per the latest DOR instructions).
- Direct deposit: Provide routing and account numbers and mark checking or savings.
Keep your confirmation or mailing proof.
Review the Return Before Submission
Before you submit, confirm:
- Filing status matches the federal return
- Residency dates are correct
- Montana-source income is identified
- Gains are classified as short-term or long-term
- Withholding and estimates match your records
- Credits are supported
- Bank details are right
Support for Complex or Cross-Border Returns
VJM Global helps U.S.-based clients, NRIs, OCIs, foreign investors and businesses with tax compliance and cross-border income questions. That support covers residential-status determination and treaty interpretation on complex or multi-jurisdiction returns.
Montana Exemptions, Subtractions, Deductions and Credits
Federal Deductions and Montana-Specific Adjustments
Montana follows the federal standard or itemized choice. The main add-back is state income tax deducted federally, limited by the federal standard deduction. Confirm details against the 2026 Form 2 instructions.
Montana-Exempt Income and Subtractions
Subtractions and deductions reduce taxable income. Credits reduce tax. An item exempt under Montana law may still appear federally and need a subtraction rather than omission.
| Item | Treatment |
|---|---|
| Pensions and annuities | Generally taxable; the old partial deduction was repealed |
| Social Security | Taxed only to the extent included in federal taxable income |
| Age 65+ subtraction | $5,660 in DOR's 2026 planning publication; confirm on the final form |
| Military retirement | Lesser of 50% of retirement income or qualifying Montana earnings; five-year limit; attach Form WMRE |
| 529 contributions | 2026: $4,600 individual, $9,200 joint |
| Other | U.S. obligation interest, Railroad Retirement, certain scholarships |
Credits That May Reduce Montana Tax
- Montana EITC: 20% of federal EITC from 2026, refundable; requires Montana residency and a federal claim. Verify the rate (DOR still shows 10%; HB 337 sets 20%).
- Other-state or foreign tax credit: Nonrefundable, capped at Montana tax on that income, with no carryover. Foreign taxes do not qualify to the extent you claimed the federal credit.
- Elderly homeowner/renter credit: Age 62+, household income under $45,000, maximum $1,150, claimed on Schedule 2EC.
2026 Filing Deadlines, Extensions and Payments
Original Return and Estimated-Tax Deadlines
| Obligation | Date |
|---|---|
| 2026 Form 2 filing and payment | April 15, 2027 |
| 2026 estimates | April 15, June 15, September 15, 2026; January 15, 2027 |
Estimated dates move to the next business day when they fall on a weekend or holiday. DOR's Publication 1 says estimates are required when you expect to owe more than $500 after withholding and nonrefundable credits. Safe harbors are 90% of current-year or 100% of prior-year tax.
Extensions and Disaster-Related Relief
Montana grants an automatic six-month filing extension with no application. It does not extend time to pay. If you receive a longer federal extension, confirm with DOR whether it also covers your Montana return before relying on it.
For IRS disaster relief, DOR offers similar relief, but its procedure describes requesting it after filing. Don't assume every IRS postponement applies automatically.
Online Payments and Payment Records
Pay through the Department of Revenue's TransAction Portal (TAP) at tap.dor.mt.gov. DOR's payment instructions list free e-check, credit or debit card (fee applies), or check with a voucher. Choose the correct tax year and payment type.
- Payment plans: Request through TAP if you have a balance due. Most requests are approved immediately.
- Interest: 7% annually for calendar 2026, computed daily.
- Late filing: 5% per month, up to 25%, with a $50 minimum.
- Late payment: 0.5% per month, up to 12%.
Save every confirmation number. Compare DOR's payment records with the amounts you report on Form 2.
Frequently Asked Questions
What is the personal income tax in Montana?
For 2026, Montana taxes ordinary taxable income at 4.7% up to $47,500 (single), $71,250 (head of household) or $95,000 (joint), and 5.65% above. Net long-term gains use separate 3% and 4.1% rates. Tax applies to Montana taxable income, not gross income.
How do I file a Montana state tax return?
Complete your federal return, then Form 2 with the needed schedules. File through approved e-file software or on paper with supporting documents. Pay any balance due by April 15, 2027.
What taxes will I be filing in 2026?
During 2026 you file tax year 2025 federal and Montana returns. Your 2026 Montana return is generally filed in 2027. Estimated payments for 2026 income are due during 2026 and in January 2027.
Do I have to file a Montana state tax return?
It depends on residency, Montana-source income, federal filing requirements, Montana adjustments and credits claimed. Confirm current thresholds with DOR's filing requirements page.
What kind of income is exempt from income tax?
Few categories are fully exempt. Many items, including Social Security and military retirement, qualify only for a subtraction or partial relief, and eligibility is fact-specific. Check the 2026 Form 2 instructions.
Can I pay my Montana income tax online?
Yes. Use TransAction Portal for balance-due and estimated payments. Select the right tax year and payment type, and keep the confirmation.
