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Updated 2025 Tax Year

Custer County
Property Tax Guide

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

9 Official Sources
8 min read
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Quick Facts
Tax Rate
Base 1% of market value plus variable mill levies by district - total rates vary significantly by location
Exemptions
4+ Available
Section 1

How Property Tax Works

Custer County, Montana operates on a property tax system that funds essential local services including schools, roads, law enforcement, and county operations. Property taxes are the primary revenue source for these services, with tax rates varying significantly based on your property's location within special taxing districts throughout the county. The county follows Montana's statewide assessment practices with properties typically assessed at a percentage of market value.

Tax rates in Custer County vary by location due to different combinations of special taxing districts such as school districts, fire districts, and other local service areas. While Montana's base assessment rate is approximately 1% of market value, your actual tax burden will depend on the specific mills levied by each taxing jurisdiction where your property is located. Property owners should expect their effective tax rates to differ from neighbors in different districts, even with similar property values.

Section 2

What Makes Up Your Tax Bill

ComponentRateDescription
County GeneralVaries by districtBasic county services and operations
School DistrictVaries by districtLocal school funding and operations
State MillsSet by legislatureStatewide property tax for state services
Fire DistrictIf applicableFire protection services
Special DistrictsVariesWater, sewer, lighting, or other local services

Note: Specific mill rates for levy year 2025 are not yet officially released by Custer County. Tax rates vary significantly based on which special taxing districts serve your property location. Contact the Custer County Assessor's Office for current rates applicable to your specific property address.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Custer 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 Custer County are additional tax bills issued when there are changes to property ownership, new construction, or corrections to assessments after the regular tax bills have been mailed. These typically occur when new structures are completed, property improvements are added, or when ownership transfers trigger a reassessment. The supplemental amount represents the difference between what was originally billed and what should have been billed based on the property changes.

For example, if you complete a home addition worth $50,000 in market value during the tax year, you may receive a supplemental bill for the additional taxes owed on that improvement, prorated for the remaining months in the tax year. The county treasurer's office will calculate the additional mills and send a separate billing notice with its own due date.

Example Calculation

Example 1: $300,000 Property

  • Market Value: $300,000
  • Assessed Value (varies by class): ~$300,000
  • Less: Property Tax Assistance Program (if qualified): Variable
  • Net Taxable Value: ~$300,000
  • Estimated Annual Tax (varies by district): $2,400-$3,600
  • Monthly Escrow: $200-$300

Example 2: $600,000 Property

  • Market Value: $600,000
  • Assessed Value: ~$600,000
  • Less: Available tax credits (application required): Variable
  • Net Taxable Value: ~$600,000
  • Estimated Annual Tax (varies by district): $4,800-$7,200
  • Monthly Escrow: $400-$600

Example 3: $1,000,000 Property

  • Market Value: $1,000,000
  • Assessed Value: ~$1,000,000
  • Less: Applicable tax credits (must apply): Variable
  • Net Taxable Value: ~$1,000,000
  • Estimated Annual Tax (varies by district): $8,000-$12,000
  • Monthly Escrow: $667-$1,000

Note: Tax credits require separate applications and are not automatically applied. Contact the county assessor for specific credit availability.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Custer County require property tax escrow accounts to ensure timely tax payments. Your lender will estimate annual property taxes and collect 1/12 of that amount with each monthly mortgage payment. These funds are held in escrow and used to pay your property tax bills when they become due on November 30th and May 31st each year.

Lenders typically conduct annual escrow analyses to adjust your monthly payment based on actual tax bills and any changes in assessed value or tax rates. If your escrow account has a shortage, you may need to make up the difference or see an increase in monthly payments. Conversely, overages may result in refunds or reduced future payments. Property owners should verify that their lender has current contact information for the Custer County Treasurer's Office at 406-874-3427 to ensure proper payment processing.

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 property taxes due in Custer County for the current fiscal year? A: First half real estate taxes are due November 30th, and the second half is due May 31st of the following year. For 2024 taxes, first half payments were due November 30, 2024.

Q: What tax credits are available and do I need to apply? A: Available programs include the Property Tax Assistance Program and Disabled or Deceased Veteran's Residential Exemption. All tax credits require separate applications - none are automatic. Contact the county assessor for application forms and deadlines.

Q: How does the homestead exemption work in Montana? A: Montana's homestead exemption typically limits assessment increases rather than reducing market value. This caps how much your assessment can grow year-over-year. You must file an application to receive this benefit - it's not automatically applied.

Q: How often are properties reassessed in Custer County? A: Montana conducts property reappraisals on a regular cycle. Contact the Custer County Assessor's Office for the current assessment schedule and appeal deadlines for your property.

Q: What are the penalties for late property tax payments? A: Late payments incur penalties and interest charges. Contact the Custer County Treasurer's Office at 406-874-3427 for current penalty rates and payment options.

Q: Can I pay my property taxes online? A: Check the Custer County website at custercountymt.gov or call 406-874-3427 for current online payment options and accepted payment methods.

Q: Why do tax rates vary within Custer County? A: Tax rates differ based on special taxing districts serving your property, such as different school districts, fire districts, or other local service areas. Properties in different districts will have different total mill rates.

Q: When is the application deadline for property tax assistance programs? A: Application deadlines vary by program. Alternative payment schedule applications are due September 30th of the taxing year. Contact the assessor's office for specific deadlines for each tax credit program.

Verified Sources

Backed by 9 Official Government Sources

Every fact in this guide is sourced from official county, state, and federal documents.

01
Treasurercustercountymt.gov
02
County
Custer County Montana – Welcome to the Official website for ...custercountymt.gov
03
County
Annual Property Tax Changes by Countyrevenuefiles.mt.gov
04
Tax Doc
Taxes Due November 30thcustercountymt.gov
05
Property Assessment Divisionsvc.mt.gov
06
Tax Doc
Property Taxesgov.mt.gov
07
State
Supplemental/Revised Real Property Statementscustercountymt.gov
08
MONTANA SUPREME COURT ORDER 23-0635 2023 ...custercountymt.gov
09
1 - Authorized Print Version – HB 816archive.legmt.gov
All sources verified as of 2025 Tax Year

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