Rate Breakdown

Property taxes in Granite County are calculated by multiplying the assessed value (minus exemptions) by the total local millage rate.

How Property Tax Works in Granite County

In Granite County, property taxes are determined by combining property valuation and local millage rates. The Montana Department of Revenue (DOR) is responsible for appraising all real property at its current market value, typically on a two-year cycle for residential properties. Once the market value is established, it is multiplied by a state-legislated tax rate to determine the property's taxable value. Local taxing jurisdictions—including Granite County, local school districts, and municipal governments—then apply their specific millage rates to this taxable value. A mill represents one-tenth of a cent ($0.001), meaning one mill generates $1 of tax for every $1,000 of taxable value. Your total annual tax bill is the sum of these various local mills plus any voter-approved bonds or special assessments.

Available Exemptions

While Montana does not offer a standard homestead exemption, several assistance programs are available to Granite County residents to help lower their property tax burden:

• Property Tax Assistance Program (PTAP): Helps low-to-moderate-income homeowners by reducing the taxable value of their primary residence based on income limits.
• Montana Disabled Veteran (MDV) Assistance Program: Offers significant property tax reductions for disabled veterans or their unmarried surviving spouses, depending on disability rating and income.
• Elderly Homeowner/Renter Credit: A refundable income tax credit of up to $1,150 for Montana residents age 62 or older who meet specific household income requirements.
• Land Value Reduction: Available for homeowners whose land value is disproportionately high compared to the value of their residential dwelling.

Payment Schedule & Deadlines

Property taxes in Granite County are billed annually but are split into two installment payments. The Granite County Treasurer mails tax bills in the fall, and payments are due as follows:

• First Half: Due on or before November 30 of the tax year.
• Second Half: Due on or before May 31 of the following calendar year.

If a deadline falls on a weekend or holiday, payments are due on the next business day. Failure to pay by these deadlines results in a 2% penalty on the delinquent amount, plus interest charged at a rate of 10% per annum until the taxes are paid in full. Delinquent properties may eventually be subject to a tax lien sale.

Appealing Your Assessment

If you believe your Granite County property assessment does not reflect fair market value, you have the right to appeal. The process begins when you receive your biennial Classification and Appraisal Notice from the Montana Department of Revenue.

• Informal Review (Form AB-26): You must file an AB-26 form with the Department of Revenue within 30 days of the date on your notice. This allows you to submit supporting evidence, such as a recent appraisal or sales of comparable properties, for a staff review.
• County Tax Appeal Board (CTAB): If you disagree with the informal review decision, you can appeal to the Granite County Tax Appeal Board. This must be filed within 30 days of the Department's decision letter.
• State Tax Appeal Board (MTAB): Further appeals can be escalated to the Montana Tax Appeal Board if the county-level decision is unsatisfactory.