Every property tax bill in the country is the same two-step sum: an assessed value, reduced by exemptions, multiplied by a rate. Everything that confuses people about property tax lives inside those steps.
The assessor assigns a market value, then applies an assessment ratio — the percentage of value that is taxable. In some states that ratio is 100%; in others it is a fraction set by statute. Your "assessed value" on the notice is usually after the ratio, not the market value, which is why it can look low.
A homestead exemption, a veteran exemption or a senior freeze reduces the taxable value before the rate is applied. These are applied per property and often require an application — they are not automatic everywhere, and unclaimed exemptions are one of the most common ways homeowners overpay.
The rate comes from the budgets of every taxing district that touches your parcel: county, city, school district, and often water, fire, library or transit districts. It is usually expressed in mills, where one mill is $1 of tax per $1,000 of taxable value.
Take a home with a $400,000 market value, an assessment ratio of 100%, a $50,000 homestead exemption, and a combined rate of 22 mills:
Change any one input and the bill moves proportionally: a successful appeal that cuts $40,000 of value saves $880 a year at that rate, every year, until the next reassessment.
Different exemptions, a different assessment year (many counties reassess on a multi-year cycle, so one house is on a stale value), different districts touching the parcel, and in some states different caps on how fast the taxable value can rise.
One mill is one dollar of tax per thousand dollars of taxable value. A 22-mill rate on $350,000 of taxable value is $7,700.
Not always. Many jurisdictions assess at a percentage of market value, and reassessment cycles mean the figure can lag the market by years.
Yes — if the rate rises by more than the value falls, or if your exemptions change. The two inputs move independently.
This guide is general; the dates that apply to you are the ones your county publishes. Look up your county or see every upcoming deadline.
CountyTaxDates is an independent reference and is not a government agency. Deadlines change and exceptions apply — always confirm with your county treasurer using the official link on this page. Nothing here is tax, legal or financial advice.