Montana · 2027 and beyond

Montana in 2027 and beyond: what is already law, and what is still open

No tax measure on the ballot. The top rate is 5.65% for 2026 and falls to 5.4% for 2027. What is on the 2026 return, what starts with tax year 2027, and what is scheduled or conditional after that.

By Charles Trautman, EA, editor

Need to Know Tax · written from Montana Department of Revenue sources and the unofficial November 3 election returns, November 12, 2026 · not yet reviewed by a Montana practitioner

No tax measure on the ballot. The top rate is 5.65% for 2026 and falls to 5.4% for 2027. This page keeps apart three things that get mixed together in the news: what is on the 2026 return you file in early 2027, what begins with tax year 2027, and what is scheduled, conditional or still undecided after that. Election figures are the unofficial November 3, 2026 returns and are not final until the state certifies them.

What the voters decided on November 3, 2026

No statewide tax measure was on the November 3, 2026 ballot in Montana. Nothing voted on that day changes a Montana return.

This return, next year, and later

Montana: what applies when
When	What applies
The 2026 return, filed in early 2027	The top rate is 5.65%, down from 5.9%, and the 4.7% bracket is wider.
	The federal deductions for tips, overtime, seniors and car-loan interest reduce Montana tax too, because Form 2 starts from federal taxable income.
	The state earned income credit is 20% of the federal credit.
Starting with tax year 2027	The top rate falls to 5.4%, applying above $65,000 single and $130,000 joint (HB 337).
Starting with tax year 2027	Enrollment for the lower homestead property tax rate closes March 1, 2027 for anyone not already in.
2028 and later, or conditional	The 2027 Legislature will decide whether the federal deductions keep flowing through; anything it does reaches the 2027 return at the earliest.

Items under 2027 and later do not change the 2026 return. They matter for 2027 withholding, estimated payments and planning. The detail behind each line is in the other Montana articles.

The 2025 federal law and the Montana return

Montana starts from federal taxable income, so it received the 2025 federal deductions by default, with no vote.

That is the reason a change on the federal return, such as the deductions for tips, overtime and people 65 and older, may or may not show up on the Montana return. The federal side is in The new deductions for tips, overtime and seniors.

What to watch

The 2027 legislative session, which opens in January. When something on this page changes, the change is logged on the updates page with its date.

What to bring

Your 2026 federal and Montana returns, once filed, to set 2027 withholding and estimated payments against them
Your last pay stub of 2026 and the first of 2027, to see whether withholding changed
Any notice from the state about a 2027 rate, credit or filing change

Questions people ask

Does anything here change the Montana return I file in early 2027?

Only what is listed under the 2026 return. Everything listed under 2027 or later affects withholding, estimated payments and planning, not the return for 2026.

How will I know if this page changes?

Every change is logged on the updates page with its date and the article it affects. State legislatures meet in early 2027 and some act before the filing deadline.

Montana, after the election

No tax measure on the ballot. The top rate is 5.65% for 2026 and falls to 5.4% for 2027.

Written by Charles Trautman, EA, editor  ·  Need to Know Tax, Lone Tree, Colorado
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Sources and where to check

Written November 12, 2026 · after the November 3 election · awaiting review by a Montana practitioner