State Guide

How to Appeal Your Property Taxes in Montana (2026 Guide)

Published July 25, 2026

Montana is unusual: your home isn't appraised by your county, it's appraised by the Department of Revenue, and the number it sets is meant to be 100% of market value. That makes a Montana property tax appeal a clean argument about one thing — what your house would actually sell for — but it also puts you on a 30-day clock that starts the day your notice is dated.

The Montana deadline: 30 days from your notice

There is no fixed statewide filing date in Montana. Your window is 30 days from the date printed on your classification and appraisal notice (MCA §15-7-102(3)(a)). Object within those 30 days and a reduction is considered for both years of the two-year valuation cycle.

That single 30-day clock covers two different moves, and you can use either:

• Form AB-26, a Request for Informal Classification and Appraisal Review, filed with the Department of Revenue. This is the cheap first rung — you explain why the classification or value is wrong and an appraiser looks again.
• A direct appeal to your County Tax Appeal Board (CTAB), submitted to your county clerk and recorder (MCA §15-15-102). You get one application for reduction per valuation cycle, and the filing date is the date the clerk stamps it.

If you file the AB-26 first, you don't lose the board: you get 30 days from the Department's decision to appeal to the CTAB. And if you missed the original 30 days entirely, Montana still lets you ask for informal review up to June 1 of the second year of the cycle — but a reduction granted then applies to that second year only, not both.

Category	Montana
Who appraises	Montana Department of Revenue (state-administered, not county)
Assessment basis	100% of market value; assessed value = appraised value (§15-8-111)
Valuation cycle	Two years for residential; the 2025–2026 cycle is valued as of January 1, 2024
Appeal deadline	30 days from the date on your classification and appraisal notice (§15-7-102(3)(a))
Where you file	Form AB-26 with the DOR, and/or CTAB via your county clerk and recorder (§15-15-102)
Assessment cap	None — the 2025 homestead relief cut tax rates, not values (§15-6-134)
Can the board raise your value?	Yes — it "may change any assessment or fix the assessment at some other level" (§15-15-101(6))
Are sale prices public?	No — realty transfer certificates are confidential (§15-7-308)

The number on your notice that isn't a ratio

This trips up a lot of Montana homeowners. Your notice shows a small percentage — for class four residential property, 0.76%, 0.9%, 1.1%, or 1.9% depending on where your value falls relative to the state's median residential value (MCA §15-6-134). That is a tax rate, not an assessment ratio. It's applied downstream to build the base your mill levies run against.

Montana appraises at 100% of market value and assessed value is the same as appraised value (MCA §15-8-111). So there is nothing to gross up. If you divide your market value by 0.0135 or by any of those class-four percentages, you will manufacture a phantom over-assessment roughly 50 to 130 times too large — and walk into a hearing with a number the appraiser will dismantle in thirty seconds.

The same distinction explains why Montana's 2025 homestead relief doesn't change your appeal. Those tiered rates lower the percentage applied to your market value; they do not cap the market value itself, which is re-set to 100% of market at each reappraisal. Montana has no assessment-growth cap standing between a value win and a lower bill — a reduction flows straight through.

Comparable sales in a non-disclosure state

Your appeal contests market value, so the evidence that wins is recent, nearby sales of genuinely similar homes — similar size, age, condition, and submarket — not listing prices or an online estimate.

Montana makes that harder than most states. The realty transfer certificate that records what a property sold for "are not a public record and must be held confidential" (MCA §15-7-308). You can't pull sale prices off a county website the way a Florida or Wisconsin homeowner can. Practically, that means your comps have to come from a licensed MLS-sourced feed — which is exactly the gap PROppeal fills.

One real risk: the board can move your value up

Montana is a can-raise state. On your own appeal, the County Tax Appeal Board "may change any assessment or fix the assessment at some other level" (MCA §15-15-101(6)) — that language is bidirectional. If your comps don't support a cut, you are not simply back where you started.

Beyond the CTAB, either side may appeal to the Montana Tax Appeal Board by the later of 45 days after the county board hearing or 30 days after the board mails its decision (the board may "affirm, reverse, or modify" it; MCA §15-2-301), and from there judicial review in district court within 60 days. Each rung is more adversarial than the last, with the state defending its own appraisal.

So the rule in Montana is simple: start with the AB-26 informal review, and only escalate when your comparable sales clearly and cleanly support a lower market value.

Get your case built

PROppeal pulls licensed comparable sales for your address, applies Montana's 100%-of-market rule (and never confuses the class-four tax rate for an assessment ratio), and tells you straight whether your appraisal is out of line — before your 30 days run out.

Property tax rules and deadlines vary by jurisdiction and can change — verify with your county before relying on this.