Why Montana Property Tax Assessments Can Be Wrong (And What You Can Do About It)

Why can your Montana property tax assessment be inaccurate—and what should you do if it is?
If the Montana Department of Revenue doesn’t have complete or accurate information about your property, they rely on assumptions. In many cases, those assumptions can lead to a higher assessed value—and a higher tax bill—than necessary.

If You Bought a Home Recently, This Matters More Than You Think

If you purchased a home in Bozeman, Livingston, Ennis, or Big Sky in the last few years, your property tax assessment is closely tied to that timing.

Montana values property on a fixed date within a two-year cycle. For the current cycle:

• 2025 and 2026 property taxes are based on market value as of January 1, 2024

That means your assessed value may reflect peak market conditions—even if prices have shifted since then.

At the same time, small inaccuracies in your property record can compound that value. That’s where many homeowners run into issues.

Appraiser Realities

 Local appraisers have acknowledged that roughly 95% of property valuations are completed from the exterior.

Sometimes that’s by necessity. Sometimes it’s because access isn’t granted.

When an appraiser can’t inspect your home, they rely on:

• Exterior observations
• Aerial imagery
• Comparable properties
• Standardized assumptions

They are required to assign a value based on available data. If key details are missing, your home is typically treated as average for the area.

In markets like Bozeman or Big Sky, “average” can be expensive.

What Appraisers Might Miss Without Access

If your property is only viewed from the road, several important details may not be captured:

• Unfinished basements counted as finished living space
• Outdated interiors assumed to be updated
• Deferred maintenance not reflected in condition ratings
• Land limitations like wetlands, steep terrain, or access challenges

For example, a 20-acre parcel outside Ennis might appear fully usable on a map. In reality, portions could be unbuildable. Without that context, the land may be overvalued.

These gaps don’t happen because of error—they happen because of missing information.

Montana Is a Non-Disclosure State—But Not in the Way Many Think

You may have heard that Montana is a non-disclosure state, meaning sale prices aren’t publicly available.

That’s partially true. But it doesn’t mean the state lacks data.

The Montana Department of Revenue receives:

• Realty Transfer Certificates (RTCs) for every recorded sale
• Property characteristics from prior records
• Sales verification forms (when returned)

In other words, the state already has a strong baseline.

The Residential Property Sales Verification Form you receive in the mail is not asking for your purchase price—it’s asking for context.

That includes:

• Interior condition
• Room counts
• Renovations or lack thereof
• Concessions that affected the sale price

Appraisers have noted that only about 10% of these forms are returned. When they aren’t, aggregate data fills the gap.

The Difference Between Value and Your Tax Bill

A key point that often gets overlooked:

• The Montana Department of Revenue determines your property’s assessed value
• Local governments (county, schools, city) apply mill levies to calculate your tax bill

This distinction matters in places like Gallatin County, where mill rates and voter-approved levies can shift over time.

Your assessed value is just one piece of the equation—but it’s the piece you can review and challenge.

Understanding the Two-Year Reappraisal Cycle

Montana moved to a two-year reappraisal cycle to better reflect changing market conditions.

For the current cycle:

• Values are based on January 1, 2024 market conditions
• Sales data from roughly mid-2023 through mid-2024 is most relevant

If you plan to challenge your value, timing matters.

Appraisers typically rely on comparable sales within this window. More recent sales may not carry weight in the current cycle.

Your 30-Day Opportunity to Correct Errors

During each reappraisal cycle, property owners will receive a classification and appraisal notice.

From the date on that notice, you have:

30 days to request an informal review (Form AB-26)

This is your opportunity to:

• Correct square footage errors
• Clarify unfinished or partially finished areas
• Provide details about condition or updates
• Request a physical inspection if needed

Local appraisers consistently recommend filing an appeal if something looks incorrect. It’s the most direct way to ensure your property is accurately represented.

The Homestead Exemption and Why It Matters

For primary homeowners, the Montana Homestead Exemption can significantly reduce taxable value.

To qualify:

• You must occupy the home at least 7 months per year
• It must be your primary residence or a qualifying long-term rental

Important timing:

• The deadline for the 2026 tax year was March 20
• The application window for 2027 is expected to reopen May 4

Missing this step can mean paying more than necessary, even if your assessed value is correct.

Practical Steps to Take Now

If you want to make sure your property is assessed accurately, here’s where to start:

Review Your Property Record

Check details through Montana Cadastral:

• Square footage
• Bedroom and bathroom counts
• Land classification

Return Verification Forms

If you receive one, complete it fully.

Watch for Your Assessment Notice

Expect it in late June or early July.

Use the 30-Day Window

File Form AB-26 if anything appears incorrect.

Confirm Your Homestead Status

Make sure your property is properly classified before the next deadline.

Local Insight from Southwest Montana

In markets like Bozeman, Livingston, Ennis, and Big Sky, property values are highly specific to:

• Location and proximity to town
• Land usability and access
• Construction quality and condition
• Zoning and potential use

At ERA Landmark Real Estate, agents regularly help clients interpret how these factors show up in real market activity—not just in automated valuations.

Understanding those differences can help you spot when an assessed value doesn’t fully align with reality

Frequently Asked Questions About Montana Property Taxes

How does Montana determine my property’s assessed value?

The Montana Department of Revenue estimates your property’s market value based on comparable sales, property characteristics, and available data. This value reflects what your home likely would have sold for on the valuation date (currently January 1, 2024).

Can refusing access to an appraiser lower my property taxes?

No. In most cases, it has the opposite effect. If appraisers cannot inspect your property, they rely on averages and assumptions, which can result in a higher assessed value.

What is Form AB-26 and when should I use it?

Form AB-26 allows you to request an informal review of your property assessment. You should file it within 30 days of receiving your appraisal notice if you believe there are inaccuracies.

What is the Residential Property Sales Verification Form?

This form helps the state understand details about your home that are not publicly available, such as condition, layout, and upgrades. Completing it can help prevent incorrect assumptions in your valuation.

What is the Homestead Exemption in Montana?

The Homestead Exemption reduces the taxable value of qualifying primary residences and long-term rentals. To qualify, you must live in the home at least 7 months per year.

What happens if I miss the Homestead Exemption deadline?

If you miss the deadline, you may pay a higher tax rate for that year. You will need to wait until the next application window to apply.

Why is my property value based on past market conditions?

Montana uses a two-year reappraisal cycle. For the 2025–2026 tax years, values are based on market conditions as of January 1, 2024, even if the market has changed since then.

Do local governments control my property value?

No. The state determines your assessed value. Local governments set the mill levies that calculate your final tax bill.

Connect with ERA Landmark Real Estate

If you have questions about your property value, recent comparable sales, or how your home fits into the current Southwest Montana market, ERA Landmark Real Estate can help you make sense of the data.

Reach out to start a conversation and better understand your position.