If you own a home in Nassau County, there's a good chance you're paying more in property taxes than you should. Nassau County consistently ranks among the top 2–3 highest property tax counties in the entire United States — and the vast majority of homeowners never challenge their assessment.
That's a mistake that costs Long Island families hundreds or even thousands of dollars every single year. This guide walks you through exactly how the grievance process works, what your odds are, and what to do when the filing window opens each January.
Nassau County's grievance period opens January 2 each year and typically closes in late February or early March. The 2027 filing window opens January 2, 2027. Don't wait — the AROW system gets congested in the final days.
What is a property tax grievance?
A property tax grievance — also called an assessment appeal — is a formal request to Nassau County's Assessment Review Commission (ARC) to reconsider the assessed value assigned to your home. Your property taxes are calculated based on that assessed value. If it's too high, you're overpaying.
Filing a grievance is not a lawsuit. It's not confrontational. It's a simple administrative process that any homeowner has the legal right to use — and one that roughly 80% of Nassau County filers have won in recent years.
There are two legal grounds for winning a grievance in Nassau County:
- Excessive assessment — your home is assessed above its actual market value. If comparable homes in your neighborhood are selling for less than your assessed value implies, you have a strong case.
- Unequal assessment — your home is assessed higher than comparable properties nearby. Even if your assessment seems reasonable in isolation, if your neighbors are paying less for similar homes, that's a valid grievance on its own.
Most successful grievances use both grounds simultaneously. You don't have to choose one.
Under New York State law, your assessment cannot be increased as a result of filing a grievance. There are only two possible outcomes: your assessment is reduced, or it stays the same. There is no downside to filing.
Why so many Nassau homeowners qualify right now
Nassau County has among the highest property taxes of any county in the United States. The median annual bill exceeds $10,000 — nearly double the national average. But beyond the general tax burden, there's a specific structural reason why an unusually high percentage of homeowners currently qualify for a reduction: the assessment freeze.
The Nassau Assessment Freeze — Why This Matters
Nassau County Executive Blakeman has frozen assessment rolls for five consecutive years. This means assessed values from years ago have been carried forward unchanged, even as actual Long Island home sale prices have risen significantly.
ARC adjusts a factor called the Level of Assessment each year to account for the gap between assessed values and real market prices. As the freeze continues and market prices climb, this multiplier keeps growing — meaning more and more homeowners are technically over-assessed relative to what their home would actually sell for.
What this means in plain English: If your assessed value is 500, ARC believes your home is worth about $930,000. If your home would actually sell for less than that — you have a case. And as the multiplier grows each year, this threshold gets easier to meet.
Other factors driving Nassau County's tax burden include top-ranked school districts (Great Neck, Jericho, Syosset, Roslyn) funded through property taxes, significant pension obligations, and limited new construction to spread the burden.
How comparables work — and why they matter
The core of any Nassau grievance is comparable sales — recently sold homes that demonstrate your assessment is higher than the market supports. This is where most homeowners go wrong when filing on their own, and where choosing the right comparables makes all the difference.
What counts as a valid comparable
- Homes that sold within approximately the past 2 years
- Same school district as your home
- Same neighborhood — ideally your street or nearby streets
- Roughly same size, style, and age
- Your own home, if you purchased it within the past 3 years
- First 5 results in AROW (ARC's own system — hardest to dispute)
- Homes that have not sold — a neighbor's lower assessment does not count
- Short sales or foreclosures
- Sales between family members
- Sales of homes with significant unrepaired damage
- Homes outside your school district
- Sales older than approximately 2 years (unless it's your own purchase)
ARC's AROW system automatically suggests comparable sales. Using the first 5 homes that appear is often the strongest strategy — ARC cannot argue you cherry-picked, and their own system generated the list. These are almost always in your immediate neighborhood and of similar size and style.
How to read the numbers
For the 2027/28 tax year, the projected Level of Assessment is approximately 0.0053, meaning you multiply your assessed value by ~1,860 to get ARC's implied fair market value for your home. If you can find good comparable sales where homes adjusted to less than your assessed value × 1,860 — you have a strong argument for a reduction.
Example: if your assessed value is 500, ARC implies your home is worth $930,000. Find recent comparable sales under that price in your neighborhood, and you have a compelling case.
Part D — the section most filers skip (don't)
Nassau's AROW application includes a section called Part D that most homeowners leave blank. For recent years, this section has become increasingly important — second-review cases may be evaluated by a real appraiser who will actually read what you write here.
Use Part D to document anything that negatively affects your home's value but isn't captured in the basic property data. You can also upload photos and supporting documents directly after submitting.
What to include in Part D
How to check your Nassau County assessment
Step 1 — Look up your assessment
Go to nassaucountyny.gov and use the Department of Assessment's property database. Your tentative assessment for the upcoming tax year is published each January.
Step 2 — Calculate ARC's implied market value
Multiply your assessed value by approximately 1,860 (the current projected multiplier). That's what ARC thinks your home is worth. If your home would realistically sell for less — you have a case.
Step 3 — Check recent sale prices nearby
Look at recent sale prices for comparable homes on Zillow, Redfin, or Realtor.com. Focus on sold prices within roughly 2 years, in your school district, with similar size and style.
Step 4 — Compare neighbor assessments
Nassau County's property search also shows neighboring assessments. If similar homes on your block are assessed lower, that's an unequal assessment argument even independent of sale prices.
When you file with GrieveItNow, we pull your assessment, run the comparable sales research, and handle all AROW filing on your behalf. Everything is included in the $99 flat fee.
What happens after you file — month by month
This is the part most guides skip. Here's exactly what happens from the moment you file through when savings appear on your bill.
January – deadline day — File your grievance
Your Application for Correction of Assessment is submitted to Nassau ARC through the AROW online system. You receive a confirmation number. That's the last active step you need to take for several months.
Spring – Summer — ARC reviews your case
Nassau ARC processes tens of thousands of grievances. They review your filing against their data and your comparable sales evidence. Nothing is required from you during this period.
Late Summer – Fall — Settlement offers arrive
ARC issues settlement offers through their ROAR system. This is where most cases resolve. You may receive an offer for a 5%, 8%, or 12% reduction in your assessed value. You can accept or reject it.
April 1 (following year) — SCAR option opens
If you're still unhappy after second review, you can file a Small Claims Assessment Review (SCAR) in Nassau County Supreme Court. The filing fee is $30. This is a formal but homeowner-accessible process where most reductions are ultimately won. GrieveItNow advises clients through this entire sequence.
October/January (following year) — Savings appear on your bill
A successful reduction appears on your October school tax bill and January general tax bill. The savings then repeat every year the reduced assessment holds — which is why re-filing annually is essential.
Should you file every year?
Yes — every single year. This surprises most homeowners, but it's one of the most important things to understand about the Nassau system.
Here's why annual filing matters even if you won last year:
- The Level of Assessment multiplier changes every year. A home that was correctly assessed last year may be over-assessed this year as the freeze continues.
- When other homeowners in your school district get reductions, the tax rate increases to cover the same budget — meaning your bill goes up even if your assessment stays flat.
- There is no downside. Your assessment cannot increase from filing. The worst outcome is no change.
- The Nassau system has not demonstrated the ability to reliably deny frivolous grievances. Until it does, filing every year is the rational choice.
The Nassau County grievance timeline — share this
Forward this to a neighbor, spouse, or family member who might be overpaying. It's risk-free and most Nassau filers get a reduction.
Nassau County Property Tax Grievance Guide
What every Long Island homeowner needs to know
GrieveItNow.com
$99 flat fee · No reduction = full refund · File opens January 2, 2027
Get Notified for 2027 →Should you file yourself or hire someone?
You can file a grievance on your own through Nassau County's AROW system — there's no filing fee and no attorney required. If you're comfortable researching comparable sales and navigating government websites, DIY is a legitimate option.
Most homeowners hire a representative because it saves time and tends to produce better-supported filings. The more important question is who you hire and what they actually charge.
The traditional model — and what it actually costs you
Most Nassau County grievance firms charge 50% of your first year's savings — every single year you re-file. On a $1,000 annual reduction, that's $500 out of your pocket year after year. Most homeowners don't realize this until they've been clients for several years.
| Traditional 50% Firms | GrieveItNow | |
|---|---|---|
| Fee structure | 50% of first year savings | $99 flat fee |
| On a $1,000 reduction | You pay $500 | You pay $99 |
| On a $3,000 reduction | You pay $1,500 | You pay $99 |
| If no reduction | No charge | Full $99 refund |
| Year 2 re-file fee | 50% again | $99 again |
| You keep (on $1K/yr reduction, 5 years) | $2,500 | $4,505 |
| Pricing shown upfront | Often buried in fine print | Always clear |
GrieveItNow was built by Chris and Stephen, two brothers who grew up on Long Island. Stephen filed his own grievance after buying his home in Northport and saved over $700 a year. Their parents in Great Neck had been overpaying for years before finally filing and receiving a reduction. They built GrieveItNow because the grievance process is straightforward — and it shouldn't cost half your savings every year to get help with it.
STAR and property tax grievances — what's the difference?
Two separate programs — both worth using
Many Nassau homeowners confuse STAR and property tax grievances, or assume one affects the other. They are entirely separate programs run by different agencies. Filing a grievance has no effect on your STAR benefit — and in fact, a successful grievance makes your STAR credit worth slightly more by lowering the base assessment it's calculated against.
A check sent directly from New York State. Consistently pays more than the exemption. If you're still on the old exemption, you're almost certainly leaving money on the table. Register at tax.ny.gov/star.
A reduction applied directly to your tax bill by the county. Has been consistently lower than the Credit in every Nassau school district for several years running. Most homeowners should switch.
Enhanced STAR is available to qualifying seniors and is significantly larger than Basic STAR. Both are separate from — and compatible with — filing a property tax grievance.
File your Nassau County grievance — $99 flat fee
We handle comparables, AROW filing, Part D documentation, and settlement offer review. No reduction means every dollar back.
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