Montana State Tax Calculator (2026)

How Montana taxes income

Montana charges 4.7% to 5.65%. State tax is a separate calculation from your federal return rather than a share of it — Montana sets its own schedule and its own definition of taxable income.

• Top marginal rate: 5.65%, reached at $47,500 for a single filer
• Brackets: 2 graduated bands, starting at 4.7%
• Standard deduction: $16,100 single / $32,200 joint
• Personal exemption: None

Rate figures are as of January 1, 2026 and come from the published Tax Foundation compilation; they have not been independently checked against Montana Department of Revenue. States do change rates mid-year, so confirm a figure there before relying on it.

What catches people out in Montana

• Montana has 2 brackets for a single filer, running from 4.7% on the first dollar up to 5.65% above $47,500.
• Montana doubles every bracket floor for joint filers, so a married couple is taxed the same as two single filers on the same combined income and the schedule carries no marriage penalty.
• The Montana standard deduction is $16,100 for a single filer and $32,200 for a couple filing jointly. It is a separate figure from the federal standard deduction and usually much smaller, so itemising is a decision you make once federally and again for the state.
• Montana's top rate was cut from 5.9% to 5.65% for 2026 by House Bill 337, with a further cut to 5.4% scheduled for 2027. The same law significantly widened the band covered by the lower 4.7% rate. Montana includes the federal standard deduction in its income starting point (footnote o).

What this estimate leaves out

Three things are deliberately outside this calculation, because they change more often than annually and a confident wrong number does real damage on a tax page.

• Personal exemptions are not applied.
• Local and city income tax is not included. New York City is the significant one nationally.
• State-specific credits, subtractions and income addbacks are out of scope and can move the result either way.

If you have income in India, Montana is where treaty relief runs out

States are not parties to the India-US tax treaty, and a state credit for "taxes paid to other jurisdictions" almost always means other US states rather than other countries.

So NRO interest, Indian rental income or a gain on Indian shares can be taxed by Montana with no credit for the Indian tax deducted at source — even though Form 1116 largely neutralises that same tax federally.

The treatment is not uniform across states, so treat this as the general position rather than as Montana's confirmed one, and check the credit rules with Montana Department of Revenue before relying on relief.

Sources

• Tax Foundation — 2026 State Income Tax Rates and Brackets
• Montana Department of Revenue — the authority for Montana