Nassau County homeowners pay some of the highest property taxes in the nation. The median effective rate sits at 2.10%, nearly double the national average of 1.02%. That gap translates to thousands of extra dollars every year. Yet, according to our Long Island homeowners survey, 39% have never filed a grievance.
Filing a property tax grievance is one of the most direct ways to reduce what you owe the county. This guide helps you decide whether it is worth your time, walks you through the process, and shows you how to get started.
Key Takeaways
Nassau County's median effective property tax rate is 2.10%, nearly double the national average, making grievances one of the most direct ways to lower your annual housing costs.
62% of Long Island homeowners have already filed a property tax grievance, nearly triple the national rate.
Filing carries no risk of a tax increase; your assessment can only stay the same or go down.
The deadline to file a Nassau County grievance is typically in March, with results arriving by fall.
You can file on your own or hire a firm like Ownwell that works on a contingency basis; you pay nothing unless your taxes are reduced.
What Is a Property Tax Grievance in Nassau County?
A property tax grievance is a formal challenge to your home's assessed value, filed through Nassau County's Assessment Review Commission (ARC). If successful, your assessed value drops, and your annual tax bill does as well.
Nassau County uses a Revised Assessed Value (RAV) system. The county multiplies your assessed value by the local tax rate to produce your bill. When the county overvalues your home, you pay more than your fair share. For a deeper look at how Nassau County calculates your property taxes, including Nassau County homestead exemptions, see our detailed guides.
Here is how the math works for a typical Nassau County home:
Before Grievance | After Grievance (10% Reduction) | |
|---|---|---|
Home market value | $650,000 | $650,000 |
Assessed value | $650,000 | $585,000 |
2.10% | 2.10% | |
Annual tax bill | $13,650 | $12,285 |
Annual savings | $1,365 |
A 10% reduction in assessed value saves this homeowner $1,365 per year.
You can file your grievance through the AROW online portal or by submitting Form RP-524 directly. Both paths lead to the same ARC review process.
Why Most Nassau County Homeowners Should File
Long Island homeowners file grievances at a rate far exceeding that of the rest of the country. Our Long Island homeowners survey found that 62% have filed a property tax grievance. Nationally, only 22% of homeowners have ever challenged their assessment.
That three-to-one gap exists for a reason. New York ranks second nationally in average annual real estate taxes, and Nassau County's burden is severe enough that filing is practically standard financial maintenance.
The same Long Island survey found that 93% of homeowners believe the system penalizes those who do not file. When nearly everyone around you is reducing their assessed value, standing still means you carry a larger share of the county's tax base.
Affordability is a top concern. 95% of surveyed Long Island homeowners expressed concern about housing affordability, with 63% saying they are highly concerned. Your tax bill is one of the few recurring housing costs you can directly challenge.
Filing a grievance carries zero risk of a tax increase. The ARC can only reduce your assessment or leave it unchanged. There is no scenario where filing raises your bill.
Nationally, 74% of homeowners have never challenged their assessment, and 57% did not even know they could. Nassau County homeowners are far more aware, but 39% still have not filed. If you're in that group, the odds are strongly in your favor.
Your Neighbors Might Be Paying Less...
Common Reasons Homeowners Don't File
Among the 39% of Long Island homeowners who have never filed a grievance, four barriers stand out:
43% assumed they would not qualify: They believed there was an income threshold or other eligibility requirement.
35% lacked awareness: They simply did not know they had the right to challenge their assessment.
16% found the process confusing: Paperwork, deadlines, and evidence gathering felt overwhelming.
6% said they distrust grievance firms: Past experiences or skepticism about third-party companies kept them from filing.
Every one of these barriers rests on a misconception. Here is how reality compares:
Myth | Reality |
|---|---|
"I probably don't qualify." | Any Nassau County property owner can file. There is no income test, home value threshold, or prior filing requirement. |
"I didn't know I could file." | 57% of homeowners nationally did not know they could challenge their assessment. It is your legal right. |
"It's too confusing." | Nassau County's AROW portal has simplified the filing process. Property tax firms, like Ownwell, handle everything from evidence to submission. |
"I don't trust grievance firms." | Contingency pricing means you pay nothing unless your taxes go down. There is no financial risk. |
The most common barrier, the assumption that you will not qualify, is the least grounded. Nassau County does not screen filers. If you own property and believe your assessment is too high, you can file.
How the Nassau County Grievance Process Works
After processing thousands of Nassau County grievances, Ownwell has found that the difference between a successful outcome and a denial almost always comes down to three to five well-chosen comparable sales. Here is the process, broken into five steps:
Check your assessed value. Look up your property on the Nassau Online Real-Property Assessment (NORA) portal. Compare the county's assessed value to what similar homes in your neighborhood have actually sold for. If the gap is meaningful, you likely have a strong case.
Gather your evidence. This step separates grievances that win from those that stall. You need comparable sales showing that homes similar to yours sold for less than your assessed value. Ownwell's proprietary software automatically scans thousands of recent transactions to identify the strongest comps.
File before the March deadline. Submit your grievance through the AROW portal or by mailing Form RP-524 to the ARC. Missing this deadline means waiting another full year.
Present your case to the ARC. The Assessment Review Commission reviews your evidence and may schedule a hearing. Ownwell represents clients at these hearings, presenting the comparable sales package and responding directly to ARC questions.
Receive your decision by fall. If the ARC rules in your favor, your assessed value drops, and your next bill reflects the savings. If denied, you can escalate to Small Claims Assessment Review (SCAR) for a second chance.
This is a simplified overview. For a full walkthrough of every step, deadlines, and forms, see the complete Nassau County property tax grievance filing guide. You can also review New York State grievance procedures for additional context on the statewide process, or explore our step-by-step Nassau County grievance walkthrough.
Skip the research and let Ownwell build your case.
DIY vs. Hiring a Property Tax Grievance Firm
You have two paths: file on your own or hire a firm to handle everything. Here is how they compare:
Factor | Filing on Your Own | Hiring a Grievance Firm |
|---|---|---|
Cost | Free | Contingency (typically 25-50% of first-year savings). Ownwell is 25%. |
Time investment | Several hours of research and preparation | Minimal; the firm handles everything |
Evidence quality | Self-gathered comps and market data | Professional market analysis with proprietary tools |
Success rate | Varies widely | Ownwell reports an 88% success rate |
SCAR escalation | You handle the process alone | The firm manages the escalation |
Filing on your own makes sense if you have experience with real estate valuations, access to recent comparable sales data, and the time to prepare and submit your case before the deadline.
Hiring a firm makes sense if you want to maximize your chances without spending hours on research. Contingency pricing means you pay nothing upfront and nothing at all if your taxes are not reduced. The firm absorbs the risk.
The 75% of Long Island homeowners who believe Nassau County's assessment system is inaccurate or inefficient have good reason to file. The question is whether you want to invest your own time or let a professional handle it.
How Ownwell Can Help
Ownwell manages the entire Nassau County grievance process from start to finish. That includes analyzing your property, building your evidence package, filing with the ARC, representing you at hearings, and escalating to SCAR if needed.
You pay nothing up front. We use contingency pricing, so you are charged only if your taxes go down.
The results speak for themselves. In Nassau County, Ownwell customers achieve an 85% success rate, save an average of $1,538, and have given the service a 4.7 rating across more than 3,000 reviews.
Ownwell also refiles your grievance annually, compounding your savings year over year.
Want to Try What Made Ownwell Famous?
Frequently Asked Questions
Can filing a property tax grievance raise my taxes in Nassau County?
No. A grievance can only reduce your assessed value or leave it unchanged. Filing will never increase your tax bill.
What is the deadline to file a property tax grievance in Nassau County?
The deadline is typically in March each year. Check the Nassau County Assessment Review Commission website for the exact date, as it can shift slightly.
How long does it take to get a decision on a Nassau County grievance?
Most decisions arrive by the fall of the same year you file. If you escalate to SCAR, the timeline may extend further.
Do I need a lawyer to file a property tax grievance in Nassau County?
No. You can file on your own through the AROW portal or with Form RP-524. Many homeowners hire a grievance firm like Ownwell instead of an attorney.
How much can I save by filing a property tax grievance?
Savings depend on how much your home is over-assessed. On a $650,000 Nassau County home, a 10% reduction saves roughly $1,365 per year. Ownwell customers in Nassau County save an average of $1,538 annually.
