Annual Property Tax Changes by County

These charts provide detailed information on tax growth in relation to economic changes in your county. The information is countywide and not specific to any individual property.

The bars in the charts show the 10-year average change in taxes for each taxing entity. These include both voted and non-voted levies in each jurisdiction. Newly voted property taxes show up as growth in collections. A new levy for a new service, say additional parks, reflects growth beyond normal inflation and population growth because it is a new responsibility of the taxing entity.

The population and inflation line measures the change in the cost of services (for which property taxes pay). Population numbers are from the Census Bureau and inflation is sourced from the Bureau of Labor Statistics. When comparing this index to the average property tax changes, the question to be answered is, “Is the average change in property taxes paid to fund these services in line with the estimated change in cost and demand for services?”

The personal income line measures growth in the economy and people’s ability to pay. Data is sourced from the Bureau of Economic Analysis and includes wages, Social Security, and business and investment income. When comparing this index to the average property tax changes, the question to be answered is, “Is income growth keeping up with the average change in property taxes paid?”

A taxing jurisdiction is a governmental entity that has taxing authority over a property. The combination of mills levied by taxing jurisdictions with authority over an individual property determines the total taxes paid. In a county, all properties pay the same number of mills to the county. If a taxpayer resides within city limits, they will also pay taxes to that city. Each property in the state is within both an elementary school district and a high school district. Additionally, all properties pay a countywide mill towards bussing and retirement. All property in the state pays state mills towards statewide education equalization and to support the Montana University System.

A mill is equal to 1/1000 of a dollar of taxable value. A levy of 10 mills is equal to 1% of taxable value. A more detailed explanation of how property taxes are calculated can be found in the Department of Revenue’s Biennial Report Property Tax Section. The average combined mill levy in the state is about 500 mills.

In general, taxing entities besides schools are limited to half the average rate of inflation of the prior three years, plus newly taxable property. Schools are limited based on average enrollment metrics. In both cases, these entities may request additional budget authority by asking voters to approve an additional mill levy. These charts do not distinguish between voted and non-voted mill levies.

These 10-year lookback charts are highly sensitive to start and end points in time. They also only show percentage growth, rather than dollar growth, which may disguise the effect of an individual taxing entity on a homeowner’s property tax bill.

Additionally, for counties with significant natural resource economies, natural resource taxes offset property taxes. The amount of taxes associated with that industry may have changed over the ten-year period. This is especially true for counties with significant oil and gas activity such as Fallon, Wibaux, and Richland. Oil and gas taxes tended to offset less property taxes in 2024 than in 2015. Although a taxing jurisdiction’s percentage increase is large relative to most other counties, their total property taxes collected remains relatively low because of this natural resource tax money.

Information on the total property taxes paid by county can found in the Department of Revenue’s Biennial Report Property Tax Section beginning on page 239. Information on taxes paid by type of property can be found in the appendix on the same webpage.

The Department of Revenue’s Property Assessment Division reappraises property every 2 years at 100% of market value; the department does not determine taxes. A large increase in market value does not necessarily correlate to a large increase in property taxes; your property’s market value is just one step in the calculation to determine taxes.

To determine the taxes on an individual property, the formula below is used.

Taxes Paid = Market Value × Tax Rate × (Mills ÷ 1000)

A property’s market value multiplied by the tax rate is the taxable value. For residential property, the tax rate is 1.35%. Other states often call this the “assessment rate”.

Example

A $400,000 residential property has a taxable value of $5,400

Market Value × Tax Rate = Taxable Value

$400,000 × 1.35% = $5,400

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Taxing jurisdictions then determine how many mills to levy each year based on their revenue authority and the total amount of taxable value in their jurisdiction. If the taxable value in a jurisdiction increases, entities reduce mills. The following is the basic formula taxing jurisdictions use to determine the number of mills to be levied on properties within the jurisdiction.

Jurisdiction Mills = (Revenue Authority ÷ Taxable Value) × 1,000

Example

City’s annual budget = $2,000,000

Total taxable value = $20,000,000

Jurisdiction Mills = ($2,000,000 ÷ $20,000,000) × 1,000 = 100 Mills

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Your property pays taxes to many jurisdictions with different mill levies. Combining all their mills and multiplying by your taxable value yields the taxes paid. Let’s assume the combined mills are 600 and solve for the tax paid on a home worth $400,000.

Example

Taxes Paid = $400,000 × 1.35% × (600 ÷ 1000)

Taxes Paid = $5,400 × 0.6

Taxes Paid = $3,240