As in "of your home". In some states, property tax is based on a formula and there is no assessing going on. In the People's Republic of California, property taxes are 1.25% of the purchase price. They then rise roughly with overall inflation over time. No assessor need be involved. But in many other states, each year your home is re-assessed often by VocabWord#305 and your taxes go up. The assessed value may have a disconnect from market value - i.e. market value (what you get from the Joneses if they want to to buy it) is often higher than the assessed value and usually if you whine enough, the assessor will make an adjustment so that for that year at least, your tax bill can come down.