What is assessed value, and how does it differ from market value?
Assessed value is the dollar value a county assessor assigns to a property for the purpose of calculating property taxes — it may differ significantly from market value, depending on local assessment ratios and state law.
Market value is what a willing buyer would pay a willing seller in an arm's-length transaction today. Assessed value is what the county says the property is worth for tax purposes. These two numbers may be the same, close, or dramatically different depending on your jurisdiction.
Most states use an assessment ratio — a percentage of market value — to set assessed value. A state might assess at 80% of market value, meaning a property worth $300,000 would carry an assessed value of $240,000. The mill rate (tax rate) is then applied to the assessed value to produce the tax bill. Some states assess at 100% of market value but apply the ratio within the rate.
Assessed values also lag the market. An assessor mass-appraises all properties in their jurisdiction on an annual or multi-year cycle; in rapidly appreciating markets, assessed values may trail actual market values by 10–30% for years at a time. In declining markets, they may temporarily exceed current market values.
For real estate investors, assessed value is a data point — not a substitute for a market analysis. It can signal whether a property is potentially under-improved (low assessed value relative to comps) or flag an unusual situation (assessed value far above neighboring properties). Tracts includes assessed land value and total assessed value for every parcel, alongside sale history, so you can compare the county's valuation against recent market transactions in the same dataset.