Montana property tax: rates, homestead rate and how to appeal

How is a Montana property tax bill calculated?

The Department of Revenue appraises the property. Its formula for the bill is: taxable value × millage rate, where the millage rate is the total mills from all jurisdictions divided by 1,000. Taxable value is market value times the class four tax rate set in MCA 15-6-134.

Each local government sets its mills within a limit. A jurisdiction’s tax revenue may grow by one-half of the average inflation rate of the past three years, plus tax on newly taxable property (MCA 15-10-420, as summarized by the Department). The department certifies taxable values to local governments on the first Monday in August. The county treasurer then bills.

What are the 2026 tax rates?

For tax year 2026, a primary residence or long-term rental is taxed in tiers. Each slice of value is taxed at its own rate, not the whole value (Department of Revenue; MCA 15-6-134(3)(b)).

The tier limits are 1, 2 and 4 times the state’s median residential value, which the department puts at $378,000. Second homes, short-term rentals and vacant residential lots pay a flat 1.9%. Tax year 2025 used different tiers: 0.76% on the first $400,000, 1.10% from $400,000 to $1.5 million and 2.20% above that.

How do you get the homestead rate?

Montana has no traditional dollar homestead exemption. The “homestead reduced rate” is a lower tax rate. To qualify, all of the following must be true (Department of Revenue FAQs):

• the home is your principal residence for at least seven months a year;
• you, or your revocable grantor trust, own it (LLCs and irrevocable trusts do not qualify);
• you are current on property taxes; and
• you claim the reduced rate on only one residence.

Enrollment matters. If you got the 2025 property tax rebate and still live in the same home, you are enrolled automatically. Otherwise you must apply. The application window for tax year 2027 runs from May 4, 2026 to March 1, 2027. A Montana “homestead declaration,” which protects equity from creditors, is a separate filing and does not give the reduced rate.

If you are buying. The reduced rate stays with a property through the end of the calendar year if it was enrolled, but the new owner must enroll to keep it the next year. If the home was not enrolled, it is taxed at the flat 1.9% for that year, and you can request a refund of the difference between January 1 and May 31 of the following year if it was your principal residence for at least seven months (Department of Revenue).

Income-based help. The Property Tax Assistance Program reduces the rate for owners with limited incomes: the statute multiplies the normal rate by 20%, 50% or 70%, depending on income, on the first $350,000 of market value (MCA 15-6-305). Income levels are adjusted each year, so check the current table with the department.

Is there a cap on assessment increases?

The sources I read set no annual percentage cap on market value. Instead, all class four real property is revalued every two years, and the value is fixed for the cycle (MCA 15-7-111). The current cycle is 2025 and 2026, with a valuation date of January 1, 2024. Local revenue growth is limited through the mill formula described above.

How do you appeal an assessment?

1. Check your property record at property.mt.gov and call your Department of Revenue field office to correct errors.
2. File a Request for Informal Classification and Appraisal Review (Form AB-26) within 30 days of the date on your notice. The department reviews evidence such as a purchase price or appraisal near the valuation date.
3. Or appeal straight to the county tax appeal board by filing with the county clerk and recorder within 30 days of the notice date. After that, the Montana Tax Appeal Board and then district court are available.

To qualify for a refund if you win, you must file a written protest with the county treasurer and pay the disputed tax under protest by the due date (MCA 15-1-402, as described by the Department).

When is Montana property tax due?

Half is due by 5 p.m. on November 30 and half by 5 p.m. on May 31 (MCA 15-16-102). Late payments owe a 2% penalty plus interest of 5/6 of 1% a month. Owners of primary residences may enroll in a seven-payment schedule under MCA 15-16-122.

Example: a $400,000 home in Billings

This is an example, not a bill. It uses the last complete adopted year, tax year 2025, and counts only two pieces: the City of Billings and the countywide Yellowstone County funds. School districts, state mills and special districts add more.

The city levied 244.39 mills in FY26 (City of Billings FY27 budget); the county’s 140.95 mills are its tax year 2025 countywide total (Yellowstone County FY27 preliminary budget). The same home as a second home in 2026 would have a taxable value of $7,600 (1.9% of $400,000), compared with $3,070.80 as an enrolled primary residence ($378,000 × 0.76% + $22,000 × 0.90%). Mills for 2026 are not yet final: the city’s budget assumes 255.39 mills, and the county’s preliminary countywide total is 129.97.

The city estimates a median Billings home at $345,200 for FY27 and the city portion of its tax at $670.02. For the full picture, see the Billings guide, closing costs in Montana and escrow accounts. Ask the county treasurer for the exact mills for your address.