If an assessed value sits above recent comparable sales, most jurisdictions publish an appeal process with a stated deadline. The ACS extract on this site does not store how often those appeals succeed.
Across the 3,137 counties with 2024 data in the U.S. Census Bureau's American Community Survey,
the average county's median property-tax bill is $1,993 a year, or $3,691 once
counties are weighted by the number of homes each one holds. The county medians are
the Bureau's; the averaging is ours. A successful appeal lowers the assessed value that bill is built on. See our methodology.
Should You Appeal?
Strong Grounds to Appeal
✓Comparable homes in your area sold for less than your assessed value
✓Your property record shows incorrect facts (wrong square footage, extra bathroom)
✓Home values in your neighborhood have declined since last assessment
✓Your property has unrepaired damage or structural issues
✓You bought the property recently at a price below the assessed value
Weaker Grounds
—Your taxes are "too high" without evidence the assessed value is wrong
—Your neighbor pays less (different exemptions may apply)
—The tax rate increased (that's a political issue, not an assessment error)
Estimate Your Potential Savings
If your assessment is reduced, your savings compound every year until the next reassessment. Use your state's detailed appeal page for a full calculator.
51
state and DC appeal routes listed
37/51
listed routes with a $0 administrative filing
Appeal Deadlines by State
Click any state for the full step-by-step appeal guide and savings calculator.
Deadlines and filing fees come from the listed state appeal-body pages. This ACS extract does not store appeal-win rates.
Frequently Asked Questions
How do I know if I should appeal my property tax?
You may have grounds to appeal if your assessed value exceeds what comparable homes in your area sold for recently, if your property record contains factual errors, or if home values in your neighborhood have declined. This site does not store a national over-assessment rate.
What is the property tax appeal deadline?
Deadlines vary by state and are typically 30–90 days after you receive your assessment notice. Most states have deadlines between March and September. See the table above for your state's typical month, and click through for exact details.
What evidence do I need for a successful appeal?
The strongest evidence is recent sales (last 6–12 months) of comparable homes ("comps") that sold for less than your assessed value. You can also use an independent appraisal, photos of property defects, or documentation of factual errors in your assessment record.
Do I need a lawyer to appeal my property tax?
No. Most homeowners successfully appeal without an attorney, especially at the initial administrative level. Small Claims Assessment Review processes (available in many states) are specifically designed to be accessible without legal representation.
How much can I save by appealing my property tax?
Savings depend on how much your assessed value is reduced and your local tax rate. For example, if your assessment drops by $50,000 and your effective tax rate is 1.5%, you save $750 per year, and that carries forward annually until the next reassessment.
Can my property tax go up if I appeal?
In most states, no. The appeal process is designed to protect you from retaliatory reassessment. However, in a few states (like New Jersey), a third party can also trigger a review of nearby properties. Read your state's rules before appealing if your property is significantly under-assessed.
Disclaimer: This guide is for informational purposes only and does not constitute legal or tax advice. Appeal deadlines and procedures vary by jurisdiction and change over time. Always verify current rules with your local assessor's office or an attorney before filing. Deadline and fee rows are sourced from the listed state appeal-body pages.
Download the county extract cited on this page:
property-tax.csv
(Census ACS county property-tax figures, CC0). Method notes live on /methodology and /data.