A mill rate in Maine is the amount of property tax charged for every $1,000 of a property’s assessed value. One mill equals one dollar per thousand, so a mill rate of 20 means $20 in tax for every $1,000 your home is assessed at. Each municipality sets its own rate every year based on how much revenue it needs and the total taxable value of property inside its borders, which is why rates look so different from one town to the next.
How a Town Arrives at Its Mill Rate
Every Maine town runs an annual tax commitment process to figure out how much money it needs to raise through property taxes. Three obligations drive that total: the municipal operating budget, the local school budget, and the county tax. County commissioners divide the county tax across every municipality in the county using state valuation figures.1Maine Legislature. Maine Code Title 30-A 706 – Apportionment of County Tax; Warrants Add them together and you have the total levy the town must collect.
To turn that levy into a mill rate, assessors divide it by the total taxable value of all property in town and multiply by 1,000. A town needing $5 million with a taxable base of $250 million lands on a mill rate of 20. If the tax base shrinks and the budget stays flat, the mill rate rises to compensate. If the base grows, a modest budget increase can be absorbed without pushing the rate up.
Assessors are also allowed to add an overlay, a small cushion that covers anticipated abatements, uncollected taxes, and rounding. State law caps the overlay at 5% of the total commitment, and the full calculation must be recorded and certified before taxes are committed to the collector for billing.2Maine State Legislature. Maine Code Title 36 711 – Assessment Record
Why Rates Vary So Much Between Towns
Maine law requires assessors to value property at its “just value,” which the statute ties to presently possible uses, physical condition, economic factors, and any legally enforceable restrictions.3Maine State Legislature. Maine Code Title 36 701-A – Just Value Defined In practice, just value tracks fair market value closely. Market prices move faster than most towns can keep up with, though, so assessed values on the books often lag behind what property would actually sell for.
That gap is measured by the assessment ratio. Each year, local assessors report their certified ratio to the state, and Maine Revenue Services accepts it as accurate if it lands within 10% of the ratio MRS calculates independently from recent sales data. If the gap is wider, the assessor has to show evidence that the local figure is more reliable.4Maine Legislature. Maine Code Title 36 685 – Duty of Assessor; Reimbursement by State
The assessment ratio is the biggest reason neighboring towns can post very different mill rates and still collect roughly similar tax per property. A town assessing at 70% of market value needs a proportionally higher mill rate to hit the same revenue target as a town assessing at 100%. A high mill rate does not automatically mean a higher tax bill.
The 70% Floor and Revaluation
Maine law requires towns to maintain assessed values at no less than 70% of just value. Contrary to a common belief, the state does not automatically order a revaluation when a town drops below 70%.5Maine Revenue Services. Understanding the Process and the Myths: Revaluations Falling below the threshold still creates problems, because recently sold properties tend to be reassessed close to market while older assessments stay stale, and equity between owners suffers. Assessors are expected to update records annually, catch new construction and lot splits, and track sales activity between full revaluations.
There’s no set cycle for a comprehensive revaluation. Some towns wait a decade or more, others move sooner. When one happens, assessed values often jump substantially, but the mill rate typically drops at the same time because the tax base has grown. The change in most tax bills is smaller than the assessment shift alone would suggest.
Calculating Your Property Tax Bill
The math is simple. Take your assessed value, divide by 1,000, and multiply by the mill rate. A home assessed at $200,000 in a town with a mill rate of 15 comes out to 200 × 15, or a tax bill of $3,000.
The assessed value in this calculation is the number on the town’s books, not what you paid or what you think the property is worth today. If your town hasn’t revalued in years, the assessed value may sit well below current market value, and the mill rate accounts for that gap. Exemptions come off the assessed value before the mill rate is applied, so the taxable figure on your bill may be smaller than the full assessment.
Exemptions That Lower the Number the Rate Multiplies
Maine offers several exemptions that reduce assessed value before the mill rate is applied. They don’t change the rate itself, but they shrink the base it acts on. All applications must be filed with the local assessor by April 1.
Homestead Exemption
The homestead exemption removes $25,000 from the just value of your primary residence.6Maine Revenue Services. Property Tax Exemptions To qualify, you must have owned a home in Maine for at least 12 months and occupy the property as your permanent residence on April 1 of the tax year. The statute sets a $10,000 base exemption plus a $15,000 additional exemption for tax years beginning on or after April 1, 2020.7Maine Legislature. Maine Code Title 36 683 – Exemption of Homesteads On a $200,000 home in a town with a mill rate of 15, the exemption drops taxable value to $175,000 and the bill from $3,000 to $2,625.
Veteran and Blind Exemptions
Veterans who served during a federally recognized war period can exempt up to $6,000 of just value on their primary residence. Those who served during or before World War I receive $7,000, and veterans who received a federal grant for specially adapted housing can exempt up to $50,000. Unremarried surviving spouses and minor children of qualifying veterans are eligible for the same exemption the veteran would have received.8Maine Legislature. Maine Code Title 36 653 – Estates of Veterans
Maine residents who are legally blind can exempt up to $4,000 of just value on their home, with the condition certified by a licensed physician or optometrist.9Maine State Legislature. Maine Code Title 36 654-A – Estates of Legally Blind Persons
Property Tax Fairness Credit
Separate from the exemptions that trim assessed value, the Property Tax Fairness Credit is a refundable state income tax credit for homeowners and renters whose property tax burden is high relative to income. Current thresholds and the maximum benefit appear on the Schedule PTFC filed with the state income tax return.10Maine Revenue Services. Property Tax Fairness Credit This one comes back through your income tax filing rather than lowering the property tax bill directly.
When Taxes Are Due and What Late Costs
Most Maine towns split the annual bill into two installments, commonly due in the fall and the following spring, but exact dates vary. Each town votes on its own due dates and prints them on the bills. Missing a deadline triggers interest on the unpaid balance.
The maximum interest rate a town can charge on delinquent taxes is set each year by the State Treasurer. For the 2026 tax year, that maximum is 7%.11Office of the Maine State Treasurer. Treasurer Perry Reduces Interest Rate on Delinquent Property Taxes The formula uses the Wall Street Journal’s published prime rate on the first business day of the year, rounded up to the next whole percent, plus three points.12Maine State Legislature. Maine Code Title 36 505 – Taxes; Payment; Powers of Municipalities Towns can vote to charge less than the maximum but not more. Interest begins on the delinquency date and becomes part of the tax itself, so it compounds.
Challenging an Assessment You Think Is Too High
If you believe your property is over-assessed, Maine law lets you file an abatement application with your local assessors. The deadline is 185 days after the town commits its taxes for the year. That commitment date is different in every municipality, so the filing deadline lands on a different calendar date in each town. Miss it and you forfeit the right to challenge that year’s assessment, with no extensions.
The application must be in writing, either on the town’s form or the standard MRS form. If the assessors don’t respond in writing within 60 days, the application is automatically considered denied and you can appeal.13Maine State Legislature. Maine Code Title 36 842 – Notice of Decision Appeals go to the municipality’s Board of Assessment Review, or, where none exists, to the county commissioners or the State Board of Property Tax Review depending on the type and value of the property.
The strongest abatement applications include recent comparable sales, an independent appraisal, or documentation of a property condition the assessor didn’t account for. Simply disagreeing with the number or pointing to a neighbor’s lower assessment rarely wins on its own.
Property in the Unorganized Territory
A large share of Maine’s land area sits in the Unorganized Territory, which has no municipal government. Maine Revenue Services handles the assessing function directly there, and the territory is treated as a single assessing unit for tax purposes.14Maine State Legislature. Maine Code Title 36 302 – Unorganized Territories Rates are set by county and tend to run lower than in organized towns because there are fewer services to fund. For the 2025 tax year, they ranged from 0.00264 in Kennebec County to 0.00938 in Franklin County.15Maine Revenue Services. Tax Rates If you own land there, your tax bill comes from the state rather than a local collector.
Where to Find a Current Mill Rate
Maine Revenue Services publishes the Municipal Valuation Return each year, compiling mill rates, assessment ratios, total valuations, and exemption data for every municipality. Assessors are required by law to file this annually.16Maine State Legislature. Maine Code Title 36 383 – Assessors Annual Return to State Tax Assessor The most recent published return covers the 2025 tax year.17Maine Revenue Services. 2025 Municipal Valuation Return A statistical summary with historical data is on the MRS property tax page.18Maine Revenue Services. Municipal Valuation Return Statistical Summary
For the most current rate in a specific town, contact the municipal assessor directly. Most towns post the current mill rate and tax commitment documents on their official website, and the MVR data can lag by several months behind recent budget votes and assessment adjustments.