Montana state income tax calculator

Estimate Montana income tax using the 4.7%/5.9% bracket schedule.

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How this calculator works

Step 1 starts with the Montana taxable income you already calculated on your return. If you are a part-year resident or nonresident, the tool applies the Montana income percentage you provide to focus on Montana-source income.

Step 2 applies Montana's two-bracket schedule (4.7% up to the filing-status threshold and 5.9% above) to estimate total tax.

Step 3 summarizes the effective and marginal rates so you can see how additional income would be taxed and whether your current estimate matches your expectations.

Frequently asked questions

What income should I enter?

Use Montana taxable income from your return. If you only know total income, estimate deductions first or use the standard deduction tool.

Do part-year residents prorate income?

Yes. Use the Montana income allocation percentage from your return to prorate taxable income before applying the Montana bracket schedule.

Does Montana have different brackets by filing status?

Yes. The 4.7% bracket ends at $21,100 single/$21,100 married separate, $31,700 head of family, and $42,200 married filing jointly. Income above those thresholds is taxed at 5.9%.

Is this tax advice?

No. This tool provides estimates based on the inputs you provide and is not legal or tax advice.

This tool provides estimates based on Montana's published brackets (4.7%/5.9%). Not legal or tax advice.

Montana state tax calculator

Quick answer

Montana uses 4.7% to 5.9% progressive income tax rates in the current TaxGuide Pro calculator data. For 2026 planning, $60,000 single taxable income -> about $3,287 state income tax before credits. $120,000 married filing jointly taxable income -> about $6,574 state income tax before credits.

Also answers

  • Montana income tax calculator 2026
  • Montana state tax estimator
  • Montana income tax brackets
  • Montana income tax rate 2026
  • Montana state tax refund status

Good fit when

  • Montana residents checking 2026 tax planning
  • Part-year or nonresident Montana filers
  • Comparing state tax, withholding, refund, and deduction scenarios

Have ready

  • Filing status and residency
  • State taxable income or benefit amount
  • Withholding, payments, deductions, credits, or filing date as relevant

Result you get

Estimated Montana tax, effective rate, marginal rate, and worked examples from current calculator data.

Montana state facts

Rate rules and worked examples

Examples use 2026 taxable income before credits or residency allocation. Use the official state source below to verify final filing guidance.

Income tax rule

Montana uses 4.7% to 5.9% progressive income tax rates in the current TaxGuide Pro calculator data.

Single example

$60,000 single taxable income -> about $3,287 state income tax before credits.

Joint example

$120,000 married filing jointly taxable income -> about $6,574 state income tax before credits.

Deductions and exemptions

Residency, local taxes, deductions, credits, and special income rules can change the result.

Credits to review

Review dependent, household, income-based, and other Montana credits in the state credit finder, then confirm eligibility in official instructions.

Filing deadline

For a 2026 return filed in 2027, confirm the due date in published Montana instructions. State deadlines and disaster relief can differ from federal dates.

Refund processing

Montana does not guarantee one refund date for every return. E-filed, accurate returns with direct deposit are generally processed faster than paper or reviewed returns.

Official verification: Montana official tax agency.

How this calculation works

  • Uses state taxable income and residency allocation.
  • Applies the calculator's current state rate schedule.

Common mistakes and caveats

  • The result is an educational estimate, not a filed return or agency determination.
  • Residency, local taxes, deductions, credits, and special income rules can change the result.
  • Verify current forms, instructions, and deadlines with the official state tax agency.

FAQ

What is the Montana income tax rate for 2026?

Montana uses 4.7% to 5.9% progressive income tax rates in the current TaxGuide Pro calculator data. The examples on this page use taxable income before credits, so final results can change when state deductions, credits, or residency allocation apply.

Does Montana tax retirement income?

Montana retirement income treatment can depend on the income type, age, and state exclusions. Use the Montana retirement tax checker for a state-specific review.

Does Montana tax Social Security benefits?

Montana Social Security treatment can differ from federal treatment. Use the Montana Social Security checker and verify the result with the official state source.

When will I get my Montana tax refund?

Montana refund timing depends on e-file versus paper filing, direct deposit, return accuracy, identity verification, and seasonal volume. Use the Montana refund timeline estimator and the official refund-status source for live updates.

Where should I verify my Montana tax result?

Use the official Montana revenue or tax agency sources linked in the sources section. TaxGuide Pro is an educational estimator and does not replace a filed state return or agency notice.

Last updated & sources

Last updated August 20, 2026.

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