Property taxes in Nassau County are among the highest in New York State — but that doesn’t mean you have to overpay. Whether your home’s assessment seems inflated or you qualify for valuable tax exemptions, there are several legitimate ways to achieve a Nassau property tax reduction and lower your annual bill.
This guide explains how Nassau County determines property values, how to challenge your assessment through a grievance, and which exemptions can save you thousands each year.
Why Your Nassau Property Tax Bill Might Be Too High
The first step in calculating your taxes is when the Department of Assessment evaluates your property's value. If your property's assessed value increases, your property taxes will also go up.
One way to determine whether your property is over-assessed is to compare the assessed value with the market value. The market value is the price your property would sell for in the current real estate market, and it's usually higher than the assessed value. If you look at a recent professional appraisal or sales prices for similar residential or commercial buildings in the area, you can get a better idea of the market value.
Another reason to appeal property taxes is that the value doesn't reflect the present condition of your home.
Assessments can be inaccurate due to:
Outdated or incorrect property data (wrong square footage, rooms, or improvements)
Neighborhood sales that don’t reflect your property’s actual condition
Unapplied or expired exemptions (like STAR or senior exemptions)
Method 1: File a Nassau County Property Tax Grievance
A Nassau County tax grievance is a formal dispute over the assessed value of your property with the Assessment Review Commission (ARC).
Step-by-Step: How to File a Grievance
Filing a property tax grievance in Nassau County can substantially lower your residential or commercial property taxes. This is how the process works:
Review the assessment roll online to see your assessment details and check for errors.
Gather evidence by collecting documentation supporting your claim, such as appraisals, photographs of structural issues, and sales prices for similar homes in your area.
File your grievance by submitting it to the Assessment Review Commission (ARC) online or with a paper form.
Appeal the ARC's decision if they offer a reduced value (known as a settlement offer) or deny your grievance. If denied, file a Small Claims Assessment Review (SCAR) petition with the Nassau County Clerk within 30 days of the final roll.
Pro tip: You don't need an attorney to file a grievance, but you can get support from property tax experts such as Ownwell.
Deadlines and Filing Windows
Meeting property tax grievance deadlines is essential if you're hoping for a property tax reduction in Nassau County, NY, because the commission will automatically deny late forms. The deadline for submitting a grievance for the 2027-28 tax year is March 2, 2026.
Method 2: Apply for Property Tax Exemptions
The second way to achieve a Nassau County property tax reduction is through property tax exemptions, which lower the assessed value of a property. Below are the most common Nassau County property tax reduction exemptions:
Exemption | Who Qualifies | How Much You Save | Where to Apply |
|---|---|---|---|
STAR Credit | Owner-occupants of primary residences | Varies by school district; usually hundreds per year | |
Senior Citizens Exemption (SCE) | Homeowners 65+ with income ≤ $58,399 (2025 limit) | Up to 50% off assessed value | |
Qualified military service | 15-25% off assessed value (plus additional combat/cold-war reductions) | Town assessor’s office | |
Disabled owners with income below local limit | Up to 50% reduction | Town assessor | |
Home Improvement Exemption | Major improvements to primary home | Gradually decreasing break over 8 years | Town assessor |
First-Time Homebuyers Exemption | Newly built or purchased homes | Partial reduction first 5 years | County/town assessor |
Note, you should combine exemptions where eligible. You can often receive multiple exemptions (for example, STAR + Veteran + Home Improvement) if you meet each program’s criteria.
Deadlines for Exemptions in Nassau County
Most exemption applications are due by January 2 for the upcoming tax year. Always verify the date on the Nassau Department of Assessment Exemptions page.
Missing the deadline means your exemption won’t apply until the next assessment cycle.
Building a Strong Appeal (and Avoiding Common Mistakes)
To strengthen your grievance:
Use recent comps (last 6–12 months) from the same neighborhood or school district.
Submit photos and estimates documenting needed repairs.
Double-check your data before submission — small errors (e.g., square footage) can lead to denial.
File before the spring deadline each year; late grievances are automatically rejected.
Common mistakes to avoid:
Submitting incomplete evidence
Failing to include your AR-1 confirmation number
Not attending ARC review sessions when requested
Additional Tips and Resources
For more guidance, Ownwell's STAR credit guide walks you through one of the most common tax reduction programs, and our Nassau County property tax guide explains the entire process from start to finish. In addition, our property tax and real estate glossary helps you better understand the terms you encounter when reading your bill and appeal forms.
You can also get information directly from the state and county governments. The Nassau County ARC guide details the appeal process and directs you to the submission page.
Get the Best Tax Reduction With Professional Help
An over-assessed property will increase your taxes, so the first step to lowering them is making sure you have a correct assessment in Nassau, NY. You can file an appeal on your own, but getting help from the best property tax reduction services in Nassau County simplifies the process and ensures you don't miss any critical steps.
Ownwell can support you with grievances and property tax exemptions in Nassau, NY.
Sign up for Ownwell to pay less and save more on your property taxes.
FAQs about Nassau Property Tax Reduction
When is the Nassau County property tax grievance deadline? The filing window for 2026 is open through March 2, 2026 for ARC submissions.
Do I qualify for the STAR exemption or credit? New homeowners apply for the STAR credit (a state refund check). If you already had the STAR exemption, you’ll continue to receive it automatically.
Can I combine multiple exemptions? Yes — homeowners may combine STAR, Veteran, and Home Improvement exemptions if they qualify for each.
What happens if my grievance is denied? You can file a Small Claims Assessment Review (SCAR) petition within 30 days of ARC’s final roll posting.
Does hiring a tax reduction firm help? Yes, especially for high-value or complex properties. Most firms charge a percentage of savings, not upfront fees.
Is it worth filing every year? Absolutely. Property values and assessment ratios change annually — successful appeals in one year don’t guarantee fair assessments next year.
