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Updated 2025 Tax Year

Lewis and Clark County
Property Tax Guide

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

10 Official Sources
8 min read
Quick Facts
Tax Rate
0.5% to 1.8% depending on taxing districts (median 0.67%)
1st Due
Nov 30
2nd Due
May 31
Exemptions
5+ Available
Section 1

How Property Tax Works

Lewis and Clark County property taxes fund essential local services including schools, law enforcement, fire protection, road maintenance, and county government operations. The county encompasses Helena, East Helena, and surrounding areas, with property taxes serving as the primary revenue source for these critical public services. Property tax bills are calculated by applying mill levies to assessed property values, with one mill equaling $1 of tax for every $1,000 of assessed value.

The effective property tax rate in Lewis and Clark County varies significantly by location within the county due to different combinations of special taxing districts. While the median rate is approximately 0.67%, individual properties may see rates ranging from 0.5% to over 1.8% depending on their specific location and the local taxing districts that serve that area. Properties are subject to various mill levies including the county general fund, school districts, city levies (if applicable), fire districts, library districts, and other special assessments. Each property's total tax rate depends on which combination of these districts serve their specific address.

Section 2

What Makes Up Your Tax Bill

ComponentRate (Mills)Description
County General~45-65Basic county services and operations
School District~180-220K-12 education funding (varies by district)
City Levy~35-55Municipal services (Helena/East Helena only)
Fire District~15-25Fire protection and emergency services
Library District~8-12Public library services
Weed District~2-4Noxious weed control programs
Special AssessmentsVariesInfrastructure improvements, bonds

Total Effective Rate: 0.5% - 1.89% depending on location and applicable districts.

Note: Multifamily rental properties valued over $2 million are subject to the higher 1.89% rate for tax year 2025. Rates are subject to change annually based on budgetary needs and voter-approved levies. Your specific tax rate depends entirely on which taxing districts serve your property address.

Section 3

When Are Property Taxes Due?

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

First Installment
Nov 30
Delinquent after Dec 10
Second Installment
May 31
Delinquent after Apr 10
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 Lewis and Clark County are triggered by significant changes to a property that occur during the tax year, primarily new construction, major improvements, or changes in property ownership that reveal previously unreported improvements. When new construction is completed or substantial improvements are made, the county assessor determines the added assessed value and applies the current mill levy to calculate the supplemental tax amount.

The supplemental tax is calculated by taking the increase in assessed value and multiplying it by the property's total mill levy rate. For example, if a homeowner completes a $50,000 addition to their home mid-year, and the assessed value increases by $40,000, with a total mill levy of 300 mills (3.0%), the supplemental tax would be approximately $1,200 ($40,000 × 0.03). This supplemental amount is prorated based on the portion of the tax year remaining after the improvement was completed, so if completed halfway through the tax year, the owner would owe roughly $600 for that year.

Example Calculation

Example 1: $300,000 Home

  • Market Value: $300,000
  • Assessed Value: $300,000
  • Homestead Credit Applied: -$25,000 (requires application)
  • Net Taxable Value: $275,000
  • Tax Rate: 2.8% (280 mills)
  • Annual Tax: $7,700
  • Monthly Escrow: $642

Example 2: $600,000 Home

  • Market Value: $600,000
  • Assessed Value: $600,000
  • Homestead Credit Applied: -$25,000 (requires application)
  • Net Taxable Value: $575,000
  • Tax Rate: 3.0% (300 mills)
  • Annual Tax: $17,250
  • Monthly Escrow: $1,438

Example 3: $1,000,000 Home

  • Market Value: $1,000,000
  • Assessed Value: $1,000,000
  • Homestead Credit Applied: -$25,000 (requires application)
  • Net Taxable Value: $975,000
  • Tax Rate: 3.2% (320 mills)
  • Annual Tax: $31,200
  • Monthly Escrow: $2,600

Note: All tax credits require separate application and are not automatically applied. Tax rates vary by specific location within the county based on applicable taxing districts.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Lewis and Clark County require property tax escrow accounts to ensure timely payment of property taxes. Your lender collects monthly escrow payments along with your mortgage payment, typically calculating 1/12th of your annual property tax bill plus a small cushion. The lender holds these funds in a separate escrow account and makes tax payments directly to Lewis and Clark County on your behalf when taxes are due.

Property taxes in Lewis and Clark County are due in two installments: April and September. Your lender will make these payments from your escrow account, and you should receive documentation showing the payments were made. Lenders are required to provide annual escrow statements showing all deposits and disbursements, and any shortages or surpluses must be addressed through adjusted monthly payments or refunds. If your property taxes increase due to reassessment or new levies, your lender will adjust your monthly escrow payment accordingly, typically with 60 days advance notice.

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 Lewis and Clark County for FY 2025-2026? A: Property taxes are due in two installments: the first half is due in April and the second half is due in September. Specific due dates are typically April 30th and September 30th.

Q: What homestead tax credit is available and how do I apply? A: Lewis and Clark County offers a homestead tax credit that provides a $25,000 reduction in assessed value for qualifying primary residences. This credit requires annual application through the county assessor's office and is not automatically applied.

Q: Are there tax credits available for senior citizens? A: Yes, elderly homeowners may qualify for additional tax credits beyond the standard homestead credit. These require separate application with income and age verification. Contact the Lewis and Clark County Assessor's office for current eligibility requirements and application deadlines.

Q: How does the homestead credit work exactly? A: The homestead credit reduces your assessed value by up to $25,000, which in turn reduces your taxable value. It does not cap assessment increases but provides a flat reduction in the amount subject to taxation. You must apply annually and the property must be your primary residence.

Q: When are properties reassessed and how can I appeal? A: Montana conducts property reassessments every two years. If you disagree with your assessment, you can appeal to the Lewis and Clark County Tax Appeal Board. Appeals must be filed within 30 days of receiving your assessment notice.

Q: What are the penalties for late property tax payments? A: Late payments incur penalty and interest charges. Penalties typically start at 2% for the first month and increase monthly. Extended delinquency can result in tax lien placement and eventual foreclosure proceedings.

Q: Can I pay my property taxes online? A: Yes, Lewis and Clark County offers online property tax payment options through their official website. You can pay by electronic check or credit/debit card, though credit card payments may include processing fees.

Q: Why do property tax rates vary within Lewis and Clark County? A: Tax rates vary because properties are served by different combinations of special taxing districts including school districts, fire districts, library districts, and municipal services. Each district sets its own mill levy, so your total rate depends on which districts serve your specific address.

Q: What triggers a supplemental tax assessment? A: Supplemental taxes are typically triggered by new construction, major property improvements, additions, or significant changes in property use that increase the assessed value during the current tax year.

Q: Do I need to apply for tax credits every year? A: Yes, most property tax credits including the homestead credit require annual application. These are not automatically renewed, and failure to reapply will result in loss of the credit for that tax year.

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