Connecticut Property Taxes Explained: Mill Rates, Grand Lists and Revaluations

For most Connecticut homeowners, the property tax bill is the largest local tax they pay. The terms on it, such as mill rate and grand list, can be confusing. This guide explains how they fit together, using state sources.

The Basics: Assessment and Mill Rate

The Office of Policy and Management (OPM) defines a mill as $1.00 of tax for each $1,000 of assessment. Under Section 12-62a of the General Statutes, towns use a uniform October 1 assessment date and assess property at 70 percent of its present true and actual value, which generally means fair market value.

Here is a hypothetical example. A home worth $400,000 would be assessed at $280,000 (70 percent). At a mill rate of 30, the tax would be $280,000 divided by 1,000, times 30, or $8,400 a year. The numbers are for illustration only and are not any town's actual rate.

The Grand List

OPM describes the grand list as the total assessed value of all taxable property in a municipality. Assessors publish it each year, by January 31, reflecting the preceding October 1 assessment date. It matters because the property tax rate is the rate that, multiplied by the grand list, produces the revenue needed to balance the budget after other income such as state and federal grants and fees. OPM notes that when the grand list grows, the mill rate will probably go down, and when it shrinks, the rate tends to rise.

How the Mill Rate Gets Set

According to OPM, the board of finance or town council decides the new budget, covering salaries, schools, equipment and local services. Other revenues, such as state and federal grants, are subtracted, and what remains is the amount to be raised through taxes. The mill rate is calculated from that amount. The proposed budget and mill rate then go to a town meeting or other legislative body, where taxpayers can discuss them and may vote.

Revaluations

A revaluation resets assessments to current market values. Under Section 12-62, every town must revalue real property on a five-year schedule. Since October 1, 2023, the dates follow a schedule OPM sets for each of five revaluation zones, which are based on planning regions. The law also requires assessors to fully inspect each improved parcel once every ten assessment years, with limited exceptions when an owner returns a verified questionnaire. You can look up your town's date on OPM's revaluation schedule page.

When a town revalues, it must mail each owner a notice showing the new value, the prior value and how to appeal to the board of assessment appeals.

A revaluation does not by itself raise the town's total tax collection. Wilton's town FAQ gives a helpful rule of thumb: if your assessment rises by a larger percentage than the town's total grand list, your bill goes up even if the budget is flat, and the reverse is also true.

Towns may also phase in assessment increases from a revaluation over up to five years, according to OPM's phase-in overview. That is a local decision.

The Motor Vehicle Tax Cap

Cars and trucks are taxed on the same mill-rate system, but with a ceiling. Section 12-71e limits the motor vehicle mill rate to 32.46 mills for the assessment year beginning October 1, 2021 and each year after. Towns may set a lower vehicle rate, including zero, and a district's rate combined with its town's rate cannot exceed the cap.

OPM says the state reimburses municipalities for revenue lost because of the cap through a grant paid by August 1 under its Municipal Revenue Sharing Fund. Beginning with the 2024 assessment year, a legislative research report says, vehicles are generally valued using the manufacturer's suggested retail price reduced for the vehicle's age. They are assessed at 70 percent of that value, and owners may appeal the MSRP used.

Where to Look Up Your Town's Rate

OPM publishes mill rates for every town and taxing district, including motor vehicle rates. OPM notes that each year's rates are based on the grand list from two years earlier.
OPM also posts the total grand list by town.
Your town's assessor can explain your property's value, and the tax collector handles bills and payment. Your town's website is the usual place to find their contact details.