How to tell whether you're over-assessed, and how to challenge it if you are.
In New York, challenging your property assessment is called "grieving" it, and almost nobody does. That is a shame, because the process is free, it needs no lawyer, and anyone who pays property taxes on a parcel can use it — owners, buyers, and tenants whose lease makes them responsible for the taxes. What it does need is a little homework, done before a deadline that comes once a year and is easy to miss.
A grievance is about one number: the assessed value of your parcel. It is not a complaint about your tax bill. Your assessor only estimates what property is worth; the tax rates are set by the school board, the town, the county and any special districts. If your assessment is fair but your taxes still feel too high, the grievance process can't help — the place to take that up is with those taxing bodies.
A grievance also only reaches the current year. You can grieve the assessment on this year's tentative assessment roll, but not an assessment from a previous year, however wrong it was.
Your assessment is not necessarily the assessor's opinion of what your property is worth. Many New York towns and cities assess everything at a fixed fraction of market value, so a $400,000 house in a town assessing at 25% would carry an assessment of about $100,000. To see what the assessor actually thinks your property would sell for, divide by that fraction:
assessment ÷ level of assessment = assessor's estimate of market value
If your municipality assesses at 100%, the two numbers are the same and there is nothing to convert. The level of assessment is published as the municipality's equalization rate or residential assessment ratio, and is often printed on the assessment roll itself as the "uniform percentage of value."
On this site, the property panel shows your total assessment and the full market value on file — that conversion already done for you. Search your address or click your lot on the map, and you have the number the rest of this guide is about. Our guide to assessed value, full market value and equalization rates explains how the numbers fit together.
The question that settles a residential grievance is simple: could you sell your home for roughly what the assessor thinks it is worth? If yes, your assessment is fair. If the assessor's figure is clearly above what it would sell for, you may be over-assessed.
The state recommends the method appraisers use: find at least three recent, ordinary sales of homes like yours — similar lot size, square footage, style, age and location — and adjust each sale price for the differences. A comparable house with an extra bathroom sold for a bit more than yours would; one on a less desirable street sold for a bit less. The adjusted prices give you a defensible estimate of your own home's value. Skip sales made under pressure, like a relocation, an estate or a divorce, since they don't reflect normal market value.
Value as of the right date, too. Assessments are based on a valuation date, which in most municipalities is July 1 of the year before the roll — so a market that has dropped since then doesn't, on its own, make this year's assessment wrong.
This site does not have sale prices, so it can't do this step for you, but it is useful for the groundwork. Clicking around your neighborhood shows how the assessor has recorded each house — year built, living area, bedrooms, bathrooms, lot size — which is how you pick genuinely similar properties. And it shows the full market value on file for each of them, so you can see whether yours stands out from comparable neighbors. The sale prices themselves come from your assessor's office, which keeps local sales records, or from online sales listings.
Before filing anything, call or visit the assessor's office. An informal conversation often clears things up on its own, especially if the record contains a plain error — the wrong square footage, a bathroom you don't have, a garage that was torn down. It is worth checking your record for exactly those kinds of mistakes first.
If you and the assessor agree that your assessment should come down, you can settle it on or before Grievance Day by signing a stipulation (Part Six of Form RP-524). Keep a copy. The trade-off: once you stipulate, you can't ask the board for more, and if the agreed assessment appears on the final roll, you can't take it to court for a lower one either.
Outside New York City and Nassau County, a grievance is filed on Form RP-524, Complaint on Real Property Assessment, with the assessor or the board of assessment review (BAR) of your town or city. You can fill it in yourself or have a representative do it.
The deadline in most places is Grievance Day itself, the day the BAR meets to hear complaints. If you mail the form, it has to arrive by then — postmarking it that day is not enough. Miss it, and you lose both the grievance and any court review of that year's assessment.
Grievance Day is usually the fourth Tuesday in May, but not everywhere:
Always confirm the date with your assessor or municipal clerk.
On the form, be careful about the value you ask for. You may not be granted a bigger reduction than you request, even if the evidence would support one. You'll also choose the grounds for your complaint. For most homeowners that is either excessive assessment (the assessor's estimate of market value is higher than what your property is worth) or unequal assessment (your property is assessed at a higher percentage of its value than other properties in your municipality). The form also covers an improperly denied exemption, an unlawful assessment, and a property placed in the wrong class.
The BAR has three to five members appointed by your town, city or village board, and none of them can be the assessor or anyone from the assessor's office — though the assessor attends and can respond to your complaint. You can appear in person, with or without a representative, and bring your comparable sales and anything else that supports your case. The burden is on you to show the board that you're over-assessed. If the board asks you to appear or answer a question and you refuse, you lose the chance of a reduction.
Afterward, you'll get a written notice of the board's decision with its reasons.
You can take your assessment to court, but only if you grieved first. There are two routes:
Either one must be started within 30 days of the filing of the final assessment roll, or of the notice of that filing, whichever is later.
RP-524 and Grievance Day don't apply in either place. In New York City, complaints go to the New York City Tax Commission, by March 15 for Class One properties (most one- to three-family homes) and March 1 for everything else. In Nassau County they go to the Assessment Review Commission by March 1. Both bodies publish their own forms and instructions.
Look up your property's assessment →The rules and dates above come from the New York State Department of Taxation and Finance's own guidance, which is the place to check anything before you rely on it: Contest your assessment, Grievance procedures, Completing the grievance form, How to estimate the market value of your home, Form RP-524, and the printable grievance booklet. SCAR filing details are on the New York State Unified Court System site. Checked against those pages in October 2026.
This guide is general information, not legal or tax advice. Procedures and deadlines vary by municipality and can change; confirm them with your assessor or a qualified professional before acting on them.