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Updated 2025 Tax Year

Carter County
Property Tax Guide

Everything you need to know about property taxes in Carter County, MT. Rates, due dates, exemptions, and how it affects your monthly payment.

10 Official Sources
8 min read
Quick Facts
Tax Rate
Varies by location due to different mill levy combinations from school districts, fire districts, and special service areas
Exemptions
4+ Available
Section 1

How Property Tax Works

Carter County, Montana operates on a property tax system that funds essential local services including schools, county operations, fire protection, and other special districts. Property taxes are the primary revenue source for these services, with tax rates determined by local mill levies set by various taxing jurisdictions within the county.

The effective property tax rate in Carter County varies by location within the county due to different combinations of special taxing districts such as school districts, fire districts, and other local service areas. Property owners may be subject to different mill levy combinations depending on their specific location. Montana uses a market value assessment system, with properties typically assessed at a percentage of their market value based on property class.

Carter County distributes approximately 76.18% of collected property taxes proportionally to current fiscal year mill levies among various local jurisdictions. Actual tax rates and effective rates depend on your property's specific location within the county and which special taxing districts serve your area.

Section 2

What Makes Up Your Tax Bill

Note: Specific mill levy rates for Carter County FY 2025-2026 are not currently available in public records. Tax rates vary significantly by location within the county based on special taxing districts.

ComponentRateDescription
County GeneralVariableBasic county services and operations
School DistrictsVariableLocal school district funding
Fire DistrictsVariableFire protection services (where applicable)
Special DistrictsVariableVarious local service districts

Important: Your actual tax rate depends on which special taxing districts serve your property location. Contact the Carter County Assessor's office at (406) 775-8749 for specific mill levy information for your property's location.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Carter County, property taxes are due in two installments:

Pro tip: If you pay through mortgage escrow, your lender splits these payments across your monthly mortgage. If you pay directly, set calendar reminders to avoid late penalties.
Section 4

Supplemental Tax Bills

Supplemental taxes in Montana are additional property tax assessments that occur when there are changes in property ownership, new construction, or improvements made to existing properties during the tax year. These taxes are calculated based on the difference between the old and new assessed values, prorated for the remaining portion of the tax year.

Supplemental taxes are typically triggered by: change in ownership that removes exemptions, completion of new construction or major improvements, or subdivision of property. The supplemental tax amount is calculated by taking the difference in assessed value multiplied by the applicable tax rate, then prorated based on the number of months remaining in the fiscal year.

For example, if a $100,000 home addition is completed in January and the local tax rate is 2%, the supplemental tax would be approximately $2,000 for the full year, or prorated based on when the improvement was completed and added to the tax rolls.

Example Calculation

Note: The following examples use estimated rates since specific Carter County mill levies for FY 2025-2026 are not available. Actual rates vary by location within the county.

$300,000 Home:

  • Market Value: $300,000
  • Assessed Value (estimated): $300,000
  • Less: Homestead Exemption: -$50,000 (if qualified and applied)
  • Net Taxable Value: $250,000
  • Annual Tax (est. 1.5% effective): $3,750
  • Monthly Escrow: $312.50

$600,000 Home:

  • Market Value: $600,000
  • Assessed Value (estimated): $600,000
  • Less: Homestead Exemption: -$50,000 (if qualified and applied)
  • Net Taxable Value: $550,000
  • Annual Tax (est. 1.5% effective): $8,250
  • Monthly Escrow: $687.50

$1,000,000 Home:

  • Market Value: $1,000,000
  • Assessed Value (estimated): $1,000,000
  • Less: Homestead Exemption: -$50,000 (if qualified and applied)
  • Net Taxable Value: $950,000
  • Annual Tax (est. 1.5% effective): $14,250
  • Monthly Escrow: $1,187.50

Note: Homestead exemption requires annual application and is not automatic.

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Section 5

Escrow & Property Taxes

Most mortgage lenders require property tax escrow accounts for Carter County properties. Your lender collects monthly tax payments as part of your mortgage payment and pays the county directly when taxes are due. Escrow payments are typically calculated by taking your annual tax bill divided by 12 months, plus a small cushion as required by federal regulations.

Property taxes in Carter County are paid in two installments: the first installment is due by November 30th of the current tax year, and the second installment is typically due in the following year. Your lender will receive tax bills directly and make payments on your behalf from your escrow account.

It's important to review your annual escrow analysis statement to ensure adequate funds are being collected. If your property taxes increase due to reassessment or mill levy changes, your monthly escrow payment may need adjustment. Starting January 1, 2026, electronic payments over $50,000 will be required for property tax payments.

How HonestCasa Helps
  • Understand whether your escrow is set correctly
  • See how rising taxes will change your monthly payment
  • Plan ahead instead of being surprised by "shortage" letters
Section 6

Frequently Asked Questions

Q: When are Carter County property taxes due? A: The first installment is due by November 30th of the current tax year, with the second installment due in the following year. Starting in 2026, electronic payments will be required for amounts over $50,000.

Q: What is the homestead exemption and how do I apply? A: Montana offers a $50,000 homestead exemption for primary residences. This reduces your taxable assessed value by $50,000. You must apply annually - it is not automatic. Contact the Carter County Assessor at (406) 775-8749 for application forms and deadlines.

Q: Are there other tax credits available? A: Various tax credits may be available for seniors, veterans, disabled persons, or low-income households. All credits require separate applications and have specific eligibility requirements. Contact the county assessor for details on available programs.

Q: How often are properties reassessed in Carter County? A: Montana requires property reappraisal cycles, but frequency can vary. Contact the Carter County Assessor's office for current assessment schedules and methodologies used in your area.

Q: How do I appeal my property tax assessment? A: Assessment appeals must be filed within specific timeframes after receiving your assessment notice. Contact the Carter County Assessor's office for appeal forms, deadlines, and procedures.

Q: What happens if I pay my property taxes late? A: Late payments are subject to penalties and interest charges. Contact the Carter County Treasurer's office for specific penalty rates and payment options if you're unable to meet the deadline.

Q: Can I pay my property taxes online? A: Contact Carter County Treasurer's office to inquire about online payment options and accepted payment methods. Electronic payments will be required for amounts over $50,000 starting in 2026.

Q: Why do property tax rates vary within Carter County? A: Different areas of the county are served by different combinations of special taxing districts (school districts, fire districts, etc.), each with their own mill levies, resulting in different total tax rates depending on your property's location.

Q: How do special districts affect my property taxes? A: Special districts provide services like fire protection, schools, or infrastructure maintenance. Each district sets its own mill levy, and your property taxes include levies for all districts that serve your area.

Q: Where can I get specific information about my property's tax rate? A: Contact the Carter County Assessor's office at (406) 775-8749 for specific mill levy information and tax calculations for your property's exact location within the county.

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