Who actually sets your Westchester assessment?
Westchester County does not assess your home. About 25 towns and cities, plus some villages that assess for their own rolls, each have their own assessor and their own Board of Assessment Review.
That means your grievance is filed with your town, city, or village, not with the county. The right office, form deadlines, and hearing dates all depend on where you live.
This is the standard New York setup outside New York City: local assessors set values, and homeowners challenge them with Form RP-524, the statewide Complaint on Real Property Assessment. Nassau County is the lone downstate exception with a county-run system.
It trips up a lot of first-time filers who call the county looking for an appeal form. Start with your local assessor's office instead.
When is Grievance Day in Westchester County?
Most Westchester towns publish their tentative roll on June 1 and hold Grievance Day on the third Tuesday in June. In 2026 that was June 16, which has just passed, so the next town Grievance Day is in June 2027.
There are exceptions worth knowing. The City of White Plains takes grievances January 1 to January 21, and several villages hold grievance dates on the third Tuesday in February for their village rolls. Confirm your own town's date before planning around the June default.
Those off-cycle dates change the planning math. White Plains homeowners get their next chance in January, which makes this fall the time to prepare there, while most towns point to June 2027.
Wherever you file, Form RP-524 must be received by Grievance Day. Postmarks do not count, and filing is free.
If you grieved this June and get a denial, ask your assessor about the SCAR deadline. Petitions for Small Claims Assessment Review are generally due within 30 days of the final roll filing, so the window after a June Grievance Day comes quickly.
How much money is at stake in Westchester?
More than anywhere else in America. ATTOM's 2025 data puts Westchester's average single-family tax bill at $18,386, the highest in the nation, with effective rates around 1.6 to 1.9 percent.
At that average bill, a 10 percent reduction saves about $1,800 a year. On a $700,000 home at roughly 1.8 percent, about $12,600 a year, a 10 percent cut still saves around $1,260 a year, every year it holds.
For context, the average US single-family bill in 2025 was $4,427, and New York's statewide average of $7,732 was fifth highest among states. Westchester homeowners pay roughly four times the national average, which is exactly why the grievance process gets so much use here.
That average also conceals a wide range across roughly 25 assessing units, so pull your own bill and run the 10 percent math on your actual number.
Why your assessed value looks nothing like your home's worth
Many Westchester rolls have not been updated in decades, so most homes are assessed at a small fraction of market value. The low number on the roll is not your market value, and it is not automatically a good deal.
To see what your assessment really claims, divide your assessed value by your town's residential assessment ratio. On Long Island, for example, a Brookhaven home assessed at just $2,400 implies a market value of about $500,000. The same kind of math applies in fractional Westchester towns with their own ratios.
A low assessed number does not mean a low bill, either. Rates are set against those fractional values, so the real question is whether your slice of the roll is too large for what your home is actually worth.
If your implied market value is higher than what your home would sell for, you have grounds to grieve. Note that a few communities, including Pelham, Scarsdale, Rye, and Mamaroneck, have run recent revaluations, so values there are fresher and the math is more direct.
How does the grievance process work?
The process runs on your town's calendar, but the steps are the same everywhere:
- Check your assessment when the tentative roll comes out, June 1 in most towns, and get your town's current assessment ratio.
- Compute your implied market value and gather recent comparable sales that test it.
- File Form RP-524 with your local Board of Assessment Review so it is received by Grievance Day.
- The board reviews your complaint. It can only lower or confirm your assessment, so filing cannot raise your value.
- If you are denied, file for Small Claims Assessment Review within the window after the final roll. SCAR costs $30, is an informal hearing, and covers owner-occupied one, two, and three family homes.
What evidence do you need?
Boards respond to market evidence, not to the size of your bill. Ask for a specific number: work out the market value your sales support, convert it back to an assessed value with your town's ratio, and put that figure on the RP-524.
Decades-old rolls also make record errors more likely. If the assessor's card still lists a garage you removed or overstates your square footage, a correction alone can move the number.
The strongest packets include:
- Recent sales of comparable homes in your town that sold below your implied market value
- The ratio math spelled out, from assessed value to implied market value
- Photos and contractor estimates for condition issues the roll does not capture
- A recent appraisal or your own recent purchase below the implied value
- Fixes to the property record, like wrong square footage, lot size, or room counts
Is grieving worth it in Westchester?
With the nation's highest average bill, the math usually says yes. Filing is free, the board can only lower or confirm, and a successful grievance keeps paying off year after year.
Two housekeeping notes. STAR, the school tax break for owner-occupied primary residences, is separate from grieving and unaffected by it. And exemption programs for things like age or veteran status are a complementary path worth checking alongside a grievance, not instead of one.
The work is in the details: your town's specific calendar, its ratio, and a persuasive comparable sales packet, assembled before a short filing window. If that sounds like a lot, Homespring manages the entire grievance for you with no upfront fee, starting well before your town's next Grievance Day.