Land value is the county's figure for the lot as if vacant. Improvement value is the figure for the building and other attachments sitting on that lot.
Land value is the county's figure for the lot as if vacant; improvement value is the figure for the building and other attachments on that lot. The same notice often splits those two numbers even when the owner thinks of the house as one price. Added together, they usually rebuild the assessed value the mills will use.
What is land value versus improvement value?
The IAAO glossary defines land value as the amount vacant land with the same location, shape, and allowable uses would bring on the open market. Improvements are the buildings, structures, and attachments meant to stay with the land. A driveway, a detached garage, and the house itself all sit on the improvement side in that vocabulary. The split is an accounting of the parcel, not a second tax.
Look up if you are overpaying.
Why does a property tax notice show both lines?
Because the roll stores them separately, and some local levies or exemptions read only one side. The homeowner still pays one bill. A property tax appeal, when one is filed, is still a fight over the total that those lines add up to. If you save, the fee FairAppeal charges is a percentage of first-year tax savings. The Fair Appeal fee never applies unless the tax actually drops.
Related reading: the property tax glossary and what a property record card is.