Reassessment is the reason your property-tax bill suddenly jumped. In most cases, your county assessor reviews home values on a schedule. When local home prices rise, your assessed value can climb too. As a result, your bill goes up, even if nothing about your house changed. However, a higher bill does not always mean a fair one. You may be overpaying. The good news is there are clear ways to check.
What Reassessment Means
Reassessment means your county assessor updates the estimated value of your home. This value is called the assessed value. It is the county’s opinion of what your property is worth. Assessors generally follow fairness standards from the International Association of Assessing Officers (IAAO). These standards aim to keep values consistent across a neighborhood.
For example, imagine home prices in your area rose last year. During the next reassessment, the assessor may raise your home’s value to match the market. Your assessed value goes up. As a result, the tax you owe can rise too. This does not mean the county is targeting you. It simply means values were refreshed.
In most cases, a reassessment happens on a set schedule. Some counties do it every year. Others do it every two, three, or five years. You can confirm your county’s schedule on your county assessor’s website. The Lincoln Institute of Land Policy also tracks how these rules differ by state.
How It Works, Step by Step
Your bill comes from two main numbers. The first is your assessed value. The second is your mill rate (the tax per $1,000 of value). You multiply them, subtract any exemptions, and get your bill. It is simpler than it sounds.
Here is a simple, illustrative example. The numbers below are made up to show the math. Your own values and mill rate vary by county and school district. Always confirm your real figures with your county assessor.
| Item | Before | After |
|---|---|---|
| Assessed value | $200,000 | $230,000 |
| Mill rate (per $1,000) | 20 mills | 19 mills |
| Homestead exemption | $25,000 | $25,000 |
| Taxable value | $175,000 | $205,000 |
| Estimated annual bill | $3,500 | $3,895 |
After a reassessment, the assessed value in this example rises. The mill rate even drops a little. Even so, the bill still goes up. This is why the timing of a reassessment matters so much. A small value change moves real money.
Why Reassessment Matters for Your Bill
Reassessment matters because it sets the base for everything you pay. A small change in assessed value can move your bill by hundreds of dollars. Over several years, that adds up fast. The Tax Foundation notes that property taxes are one of the biggest costs of owning a home.
However, a reassessment is not always correct. Assessors handle thousands of homes at once. Mistakes happen. Your record may list the wrong square footage. It may show a finished basement you do not have. These simple errors can inflate your value.
The U.S. Census Bureau shows that property-tax bills vary widely by state and county. So your neighbor’s bill is not a perfect guide. What truly matters is whether your own reassessment reflects your home accurately. That is the number you can check.
What to Do With This
Start by reading your notice closely. Check the assessed value and the listed property details. Look for any exemption you may qualify for. Many homeowners miss exemptions for a primary home, seniors, veterans, or disability. These can lower what you owe.
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For example, a homestead exemption reduces the value that gets taxed. Rules and amounts reset each year and vary by state. Confirm the exact exemption, amount, and deadline with your county assessor. Do not rely on last year’s numbers. They may have changed.
If the value still looks too high, you can usually appeal. Most counties give you a short window after the reassessment notice arrives. Gather recent sale prices of similar nearby homes. File before the deadline. You may lower your bill, though no result is ever guaranteed.
Frequently Asked Questions
Why did my property taxes go up when I did not change anything?
In most cases, a reassessment raised your home’s assessed value. Rising home prices in your area usually drive this. Your bill can climb even when your house stays exactly the same.
How often will my home be re-valued?
It depends on your county. Some re-value every year. Others do it every few years. Check your county assessor’s website for the exact schedule in your area.
Can I really lower my property-tax bill?
Often, yes. You can claim missed exemptions or appeal a value that looks too high. Results are never guaranteed. However, many homeowners find errors worth correcting.
What is the difference between assessed value and market value?
Market value is what a buyer would likely pay today. Assessed value is the county’s figure used for taxes. In many places, the assessed value is a set percentage of market value.
Where do I get the correct current numbers?
Always ask your county assessor for your current rate, exemptions, and deadlines. These figures reset each year. State Departments of Revenue also post general rules and definitions online.
See your state’s real numbers
Property tax is the most local tax there is, so the details depend on where you live. See your state’s median rate, typical bill, exemptions, and appeal deadline in one place.
Lowering your tax bill? Check your home insurance too.
Property tax isn’t the only home cost worth a second look. Many homeowners are overpaying for home insurance without knowing it — comparing quotes is a fast way to keep more of your money.
Sources & How to Verify
The figures and rules on this page come from official and authoritative sources. Property tax rates, median bills, and exemption amounts reset every year and vary by state, county, and school district — so always confirm the current figure, any exemption, and any deadline with your county assessor before you act. We are an independent educational resource, not a government agency or a tax-appeal service, and this page is not legal, tax, or financial advice.
- Tax Foundation: taxfoundation.org — property taxes by state & county
- U.S. Census Bureau: census.gov — median property tax paid and home values
- Lincoln Institute of Land Policy: lincolninst.edu — property-tax research and the 50-state data
- IAAO (assessment standards): iaao.org — how assessors are supposed to value property
- Your county assessor & state Department of Revenue: search “[your county] assessor” for your exact rate, exemptions, and appeal deadline
Content last reviewed July 2026. If you notice an outdated figure, please contact us.
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- How to Appeal & Lower Your Property Taxes
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- Property Tax Basics
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- Property Tax by State
- Property Tax Glossary
Informational only — not legal, tax, or financial advice. Know Property Tax is an independent educational resource, not a government agency, a county assessor, a law firm, or a tax-appeal service, and this page does not provide legal, tax, or financial advice. Property tax rates, median bills, exemption amounts, and deadlines change every year and vary by state, county, and school district, and any estimate is illustrative only. Always confirm your rate, any exemption, and any deadline with your county assessor and a licensed professional before you act.