HonestCasa logoHonestCasa
Updated 2025 Tax Year

Sweet Grass County
Property Tax Guide

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

8 Official Sources
8 min read
Quick Facts
Tax Rate
Varies by district - typically 1.2% to 2.5% of market value depending on location and local mill levies
1st Due
Nov 30
2nd Due
May 31
Exemptions
5+ Available
Section 1

How Property Tax Works

Sweet Grass County, Montana operates under a property tax system that funds essential local services including schools, county government operations, emergency services, and infrastructure maintenance. Property taxes are the primary revenue source for these services, with tax bills calculated based on the assessed value of your property multiplied by the applicable mill levy rates.

Montana's property tax system uses a market value approach where properties are assessed at their full market value, with different classes of property taxed at varying percentages. In Sweet Grass County, your actual tax rate will depend on your specific location within the county, as different areas are served by various special taxing districts such as school districts, fire districts, and other local service areas. The effective tax rate typically ranges around Montana's statewide average of approximately 1%, though this can vary significantly based on your property's location and the specific combination of taxing districts that serve your area.

Section 2

What Makes Up Your Tax Bill

ComponentEstimated Rate (Mills)Description
County GeneralVariesBasic county services and administration
School DistrictVariesLocal elementary and high school funding
State MillsVariesState-mandated levies for various purposes
Fire DistrictVariesLocal fire protection services (if applicable)
Special DistrictsVariesAdditional local services (varies by location)

Note: These rates apply to the current levy year and are expressed in mills (1 mill = $1 per $1,000 of assessed value). Your actual tax rate depends on which special taxing districts serve your specific property location within Sweet Grass County. Contact the Sweet Grass County Assessor's office for the exact mill levy rates applicable to your property address.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Sweet Grass 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 Sweet Grass County are additional property tax assessments that occur when there are changes to a property's assessed value during the tax year. Common triggers include new construction, completion of improvements, changes in property ownership that affect exemption status, or corrections to the original assessment.

When supplemental taxes are issued, they are calculated based on the difference between the new assessed value and the previous assessed value, multiplied by the applicable tax rate for the remaining portion of the tax year. For example, if you complete a home addition worth $50,000 in March, you would owe supplemental taxes on that additional assessed value from March through the end of the tax year. The county assessor will mail a separate supplemental tax bill, which typically has its own due date separate from your regular property tax payments.

Example Calculation

Example 1: $300,000 Home

  • Market Value: $300,000
  • Assessed Value: $300,000 (residential property)
  • Less: Homestead Tax Credit (if applied): Varies
  • Net Taxable Value: ~$290,000 (estimated)
  • Annual Tax (est. 1.0% effective rate): $2,900
  • Monthly Escrow: ~$242

Example 2: $600,000 Home

  • Market Value: $600,000
  • Assessed Value: $600,000 (residential property)
  • Less: Homestead Tax Credit (if applied): Varies
  • Net Taxable Value: ~$585,000 (estimated)
  • Annual Tax (est. 1.0% effective rate): $5,850
  • Monthly Escrow: ~$488

Example 3: $1,000,000 Home

  • Market Value: $1,000,000
  • Assessed Value: $1,000,000 (residential property)
  • Less: Homestead Tax Credit (if applied): Varies
  • Net Taxable Value: ~$980,000 (estimated)
  • Annual Tax (est. 1.0% effective rate): $9,800
  • Monthly Escrow: ~$817

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

See How Taxes Affect Your Payment

Property taxes are just part of your total monthly cost. Get the full picture.

Calculate Now
Section 5

Escrow & Property Taxes

Most mortgage lenders in Sweet Grass County require borrowers to maintain an escrow account for property tax payments, especially when the loan-to-value ratio is above 80%. Your lender collects monthly escrow payments along with your mortgage payment and holds these funds to pay your annual property tax bill when due.

Property tax bills in Sweet Grass County are mailed once annually, with the first half payment due by November 30th and the second half typically due by May 31st of the following year. Your lender will receive the tax bill and make payments directly to Sweet Grass County on your behalf. It's important to verify that your lender has the correct mailing address with the county treasurer's office to ensure timely receipt of tax bills. You should also review your annual escrow analysis statement to ensure adequate funds are being collected for property tax payments, as changes in assessed value or tax rates may require escrow adjustments.

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 Sweet Grass County? A: The first half of real property taxes is due by November 30th, and the second half is typically due by May 31st of the following year. Mobile home taxes follow a different schedule with the first half due May 31st.

Q: What tax credits are available and do I need to apply? A: Montana offers various tax credits including the Homestead Tax Credit and credits for seniors, veterans, and disabled persons. All tax credits require a separate application - they are not automatically applied to your property.

Q: How does the Homestead Tax Credit work? A: The Homestead Tax Credit limits the annual increase in your property's assessed value for tax purposes, rather than reducing the market value. You must apply for this credit - it is not automatic and must be renewed periodically.

Q: How often are properties reassessed in Sweet Grass County? A: Montana law requires properties to be reappraised at least once every six years, though market value adjustments may occur annually. Contact the Sweet Grass County Assessor's office for specific reassessment schedules.

Q: What are the penalties for late property tax payments? A: Late payments typically incur penalties and interest charges. Contact the Sweet Grass County Treasurer's office for current penalty rates and payment options.

Q: Can I pay my property taxes online? A: Check with the Sweet Grass County Treasurer's office for available online payment options and accepted payment methods.

Q: How do special district taxes affect my bill? A: Special districts for services like fire protection, schools, and other local services add their own mill levies to your tax bill. Your total rate depends on which districts serve your specific property location.

Q: How do I appeal my property assessment? A: Assessment appeals must be filed with the Sweet Grass County Tax Appeal Board within specific deadlines. Contact the County Assessor's office for appeal procedures and deadlines.

Q: What happens if I disagree with a supplemental tax assessment? A: You can appeal supplemental assessments through the same process as regular assessments. Contact the County Assessor's office immediately if you believe a supplemental assessment is incorrect.

Q: Are there exemptions for agricultural or forest land? A: Montana provides special assessment classifications for agricultural and forest lands. These require specific applications and proof of qualifying use. Contact the County Assessor for detailed requirements.

See the Full Picture of Your Home Costs

Property taxes are just one piece of homeownership. HonestCasa helps you understand your total monthly cost and explore safe ways to access your home equity.

Total Monthly Cost

Mortgage + taxes + insurance + HOA

Equity Growth

Track how your equity grows over time

Safe Equity Access

Options for projects or debt payoff

Free • No credit check • 2-minute estimate