AppealDesk

Nassau County Property Tax Grievance, New York

Travis BunnTravis Bunn·Updated July 24, 2026

Nassau County is located on western Long Island, bordered by Queens to the west and Suffolk County to the east, with a population of approximately 1.4 million residents. The county seat is Mineola, and it includes major population centers like Hempstead (the largest town with over 764,000 residents), Oyster Bay, and the cities of Long Beach and Glen Cove. Property tax grievances are especially critical here because Nassau County has the second-highest median property taxes in the United States at $8,711 annually, and property owners pay more than 4 times the national average. With a median home value of $487,900 and an effective tax rate of 1.79%, Nassau County homeowners face one of the heaviest tax burdens in the nation, making assessment challenges a vital tool for reducing excessive tax bills.

Notable cities: Hempstead, Oyster Bay, Long Beach, Glen Cove, Mineola, Freeport, Valley Stream

Median Home

$487,900

Tax Rate

1.79%

Annual Tax

$8,711

Population

1,398,939

On the typical Nassau County home, valued near $487,900 at the county’s effective tax rate of 1.79%, an over-assessment of even 10% means you are overpaying year after year until you grieve it. Here is how to find out if yours qualifies.

2026 Grievance Deadline: March 31, 2026

The Nassau County Assessment Review Commission (ARC) filing period for the 2026/27 tax year opens January 2, 2026, and closes March 31, 2026. Traditionally the deadline was March 1, but it has been extended to March 31, 2026, due to increased demand. Applications must be filed or postmarked by the USPS no later than March 31, 2026. Missing this deadline means you cannot challenge that year's assessment regardless of merit.

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Row of classic New York brownstones. Nassau County grievance guide.

How Nassau County Assesses Property

100%of market value

Assessed by: Nassau County Department of Assessment

Assessment cycle: annual

Notices typically mailed: January (tentative roll published January 2)

Nassau County assesses all properties at 100% of market value, meaning your assessed value equals your home's fair market value with no adjustment ratio. For example: If your home's market value is $487,900, at Nassau County's 100% assessment ratio your assessed value would be $487,900, resulting in approximately $8,733 in annual property taxes at the county's effective rate of 1.79%. This makes it crucial to ensure your market value assessment is accurate, as every dollar of overassessment directly increases your tax bill.

The Grievance Process

Appeals are heard by the Board of Assessment Review. After filing, the Assessment Review Commission (ARC) reviews your application and supporting evidence, which can take several months. If ARC offers a reduction, you'll receive a stipulation to accept or reject; if denied or insufficient, you can proceed to Small Claims Assessment Review (SCAR) for a formal hearing where you present your evidence before a hearing officer.

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Step 1: Review your tentative assessment notice published January 2, 2026, on the Nassau County Department of Assessment website or property search tool to confirm your property's market value and assessed value.

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Step 2: Research comparable property sales in your neighborhood from the past three years using the ARC sales locator tool available through AROW to gather evidence that your assessment exceeds market value.

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Step 3: File your grievance through the Assessment Review Commission (ARC) online via AROW between January 2 and March 31, 2026, providing your contact information, property address or parcel ID, your estimate of market value, and supporting comparable sales data.

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Step 4: Wait for ARC to review your application - the commission has until March 31 of the following year to review all grievances and will send you a proposed reduction offer if warranted, which you can accept or reject.

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Step 5: If you reject ARC's offer or receive no reduction, file a Small Claims Assessment Review (SCAR) petition by April 30, 2026, for a $30 filing fee to have your case heard in a hearing before a hearing officer.

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Step 6: If SCAR does not provide satisfactory results, you may file an Article 7 tax certiorari proceeding in New York Supreme Court within the statutory window, which generally runs concurrently with SCAR filing deadlines.

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Step 7: If successful at any level, your approved reduction will appear on your October 2026 school tax bill and January 2027 general tax bill as lower taxes, or you may receive a refund check or credit.

Required form: Application for Correction of Assessment (AR-1 form) - available through AROW online portal or as paper form from ARC

Filing Methods

online:AROW (Assessment Review on the Web) at www.nassaucountyny.gov/arc/arow or www.askarcnassau.com - recommended method with immediate confirmation and ability to track status
mail:Mail to Assessment Review Commission, 240 Old Country Road, 5th Floor, Mineola, NY 11501 - must be postmarked by March 31, 2026
in-person:Hand deliver to Assessment Review Commission, 240 Old Country Road, 5th Floor, Mineola, NY 11501 - Hours: 9:00 AM to 4:30 PM, Monday-Friday

Evidence to Bring

Comparable sales data from similar homes sold in your area within the past three yearsPhotos showing property condition, damage, or needed repairsRepair estimates or contractor invoices for structural issuesAppraisal reports from licensed appraisersEvidence of assessment inequality compared to similar propertiesDocumentation of errors in property characteristics (square footage, bedrooms, bathrooms)

Nassau County Assessor Contact

Nassau County Department of Assessment

Phone: (516) 571-1500

Address: 240 Old Country Road, 4th Floor, Mineola, NY 11501

Website: https://www.nassaucountyny.gov/1501/Assessment

Online Portal: https://www.nassaucountyny.gov/arc/arow

Hours: Monday - Friday, 8:00 AM - 4:30 PM

Tax Exemptions in Nassau County

STAR (School Tax Relief) Program

Varies by program - Basic STAR for homeowners with income under $500,000; Enhanced STAR for seniors 65+ with income below $110,700 (as of 2026-2027)

Provides relief on school property taxes for primary residences. Basic STAR is available to all eligible homeowners; Enhanced STAR is for seniors 65+ with income limits.

Eligibility: Must own and occupy a 1-3 family home, condo, co-op, or mobile home as primary residence. Enhanced STAR requires age 65+ and income limits. New purchasers after 2015 receive STAR as a credit check from NYS rather than an exemption.Deadline: Register through NYS STAR Resource Center at tax.ny.gov/star

Senior Citizens Property Tax Exemption

5% to 65% reduction based on income - maximum income to qualify is $58,399 or less

Reduces taxable assessed value for homeowners 65 or older with limited income, applying to school, county, and town taxes (special districts excluded).

Eligibility: Must be 65 or older, own and occupy the property as primary residence, and have combined household income of $58,399 or less (includes Social Security and non-taxable income, but excludes welfare, SSI, gifts, and inheritances). Unreimbursed medical expenses and Veterans Disability Compensation can be deducted.Deadline: January 2, 2026 for the 2026-27 tax year - requires annual renewal after five consecutive years

Veterans Property Tax Exemption

Up to 15% reduction on County, Town, Village, and Highway taxes, with an additional 10% for combat service or Expeditionary Medal. Disabled veterans receive up to 50% based on disability rating. School tax reductions only in participating districts.

Provides property tax reduction for veterans who served during wartime periods including Cold War veterans, with additional benefits for disabled veterans.

Eligibility: Veterans who served in U.S. Armed Forces during eligible wartime periods including Cold War, or their surviving spouses or Gold Star parents. Property must be primary residence. Reservists on active duty training are not eligible.Deadline: Contact Nassau County Department of Assessment Veterans Exemption Division at (516) 571-1500

Persons with Disabilities and Limited Income Exemption

5% to 50% reduction of assessed value based on income level - maximum income cannot exceed $58,399

Provides tax relief to homeowners with physical or mental impairments who are substantially unable to engage in major life activities.

Eligibility: Must have physical or mental impairment substantially limiting major life activities. Those impaired due to current use of alcohol or illegal drugs are not eligible. Income limits apply similar to Senior Citizens exemption. Automatically converts to Senior Citizen exemption at age 65 if eligible.Deadline: January 2, 2026 for the 2026-27 tax year

Volunteer Firefighters and Ambulance Workers Exemption

10% exemption on the property's assessed value

Provides property tax exemption for active volunteer firefighters and ambulance workers with at least two years of service.

Eligibility: Must be enrolled as active member of volunteer fire department or ambulance service for at least two years (some sources indicate five years). Exemption applies only to primary residence within the jurisdiction served by the department or company.Deadline: Contact Nassau County Department of Assessment at (516) 571-1500

Home Improvement Exemption

Eight-year decreasing exemption on the increased value from improvements - applies only to main structure improvements

Provides an eight-year decreasing property tax break for permitted improvements to one- and two-family homes that increase assessed value.

Eligibility: Eligible improvements include additions (new rooms, finished basements or attics, dormers), garage or porch conversions, central air systems, and full renovations. Does not apply to sheds, pools, landscaping, cosmetic upgrades, fixture replacements, or temporary features.Deadline: Contact Nassau County Department of Assessment at (516) 571-1500

Nassau County Grievance Packet · $49

Comparable sales evidence, county-specific filing guide, and professional cover letter. Enter your address to get started.

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Frequently Asked Questions

What is the deadline to grieve my property taxes in Nassau County for 2026?
The deadline to file a property tax grievance in Nassau County for the 2026/27 tax year is March 31, 2026. The filing period opens January 2, 2026, and you must submit your Application for Correction of Assessment to the Assessment Review Commission (ARC) between these dates. Traditionally the deadline was March 1, but Nassau County granted a rare extension to March 31, 2026, due to increased demand. If you mail your application, it must be postmarked by the USPS no later than March 31, 2026. Missing this deadline means you cannot challenge that year's assessment regardless of merit, even with a valid excuse.
How do I file a property tax grievance in Nassau County online?
You can file a property tax grievance online through AROW (Assessment Review on the Web), Nassau County's free online grievance portal, between January 2 and March 31, 2026. Visit www.nassaucountyny.gov/arc/arow or www.askarcnassau.com to access the system. You'll need your property address or parcel ID (Section/Block/Lot), your estimate of market value, contact information, and a valid email address. Filing online is the recommended method because you receive immediate confirmation with an appeal number, can track your application status, and receive electronic notifications from ARC. AROW also provides access to a sales locator tool to research comparable properties for your evidence.
What is the Senior Citizens Property Tax Exemption worth in Nassau County?
The Senior Citizens Property Tax Exemption in Nassau County can reduce your taxable assessed value by 5% to 65% depending on your income level, potentially saving thousands of dollars annually. To qualify, you must be 65 or older and have a combined household income of $58,399 or less. For example, if your home is assessed at $487,900 and you qualify for the maximum 65% reduction, your taxable value drops to approximately $170,465, saving you roughly $5,676 per year at the 1.79% effective rate. The exemption applies to school, county, and town taxes but excludes special district taxes. You must apply by January 2, 2026, for the 2026-27 tax year.
What happens after I file a grievance with the Nassau County Assessment Review Commission?
After you file your grievance with the Nassau County Assessment Review Commission (ARC), the commission reviews your application and supporting evidence, a process that can take several months up until March 31 of the following year. ARC will mail you a determination, and if they agree your assessment is excessive, they'll send a proposed reduction offer in the form of a stipulation that you must accept or reject within a specified time. If you accept, the reduction will appear on your October 2026 school tax bill and January 2027 general tax bill. If ARC denies your grievance or you reject their offer, you can file a Small Claims Assessment Review (SCAR) petition by April 30, 2026, for a $30 fee to have a formal hearing before a hearing officer.
How much can I save by grieving my property taxes in Nassau County?
The savings from grieving your property taxes in Nassau County depend on how much your property is overassessed. On the typical Nassau County home valued at $487,900 with an effective tax rate of 1.79%, even a 10% reduction in your assessed value would save you approximately $873 per year in property taxes. If your assessment is reduced by 20%, you'd save roughly $1,746 annually. These savings continue year after year until the next countywide reassessment. Given that Nassau County has some of the highest property taxes in the nation with a median tax bill of $8,711, even modest reductions can result in substantial savings over time, making the grievance process well worth the effort for overassessed properties.
What evidence do I need for a successful Nassau County property tax grievance?
To win a Nassau County property tax grievance, you need to prove your property's market value is lower than the Department of Assessment's valuation using comparable sales data from similar homes in your area sold within the past three years. The ARC online sales locator tool can help you identify comparable properties with similar square footage, age, condition, and features. Additional strong evidence includes a professional appraisal from a licensed appraiser, photographs documenting property damage or needed repairs, contractor estimates or invoices for structural issues, and documentation of errors in your property's characteristics (such as incorrect square footage, number of rooms, or lot size). You can also demonstrate assessment inequality by showing similar neighboring properties are assessed at lower values than yours.
Can I file a Nassau County property tax grievance without hiring a lawyer or tax reduction company?
Yes, you can absolutely file a Nassau County property tax grievance on your own without hiring an attorney or representative - no professional representation is required. The Assessment Review Commission (ARC) designed the AROW online portal to be user-friendly for homeowners to file directly, and the process is free with no filing fees. You'll need to gather comparable sales data using ARC's sales locator tool, complete the Application for Correction of Assessment form, and provide evidence supporting your claim that your assessment is excessive. While filing yourself is possible and can be successful, professional representation may increase your odds of success and save you time, especially for complex cases or if you're unfamiliar with property valuation methods and assessment law.
What is the difference between market value and assessed value in Nassau County?
In Nassau County, there is essentially no difference between market value and assessed value because the county uses a 100% assessment ratio, meaning properties are assessed at full market value. If the Department of Assessment determines your home's market value is $487,900, your assessed value will also be $487,900, and your taxes are calculated directly on that amount at the effective rate of 1.79%. This differs from many New York counties that use fractional assessment ratios. The 100% ratio makes it straightforward to understand your tax calculation but also means that every dollar your market value is overstated directly translates to higher taxes, which is why accurately challenging an excessive market value assessment through the grievance process is so important in Nassau County.

Official Resources

Nassau County Assessment Review Commission (ARC) →

Official ARC page with information about filing grievances, AROW online portal access, and FAQs about the assessment review process.

AROW - Assessment Review on the Web Online Filing Portal →

Online portal to file property tax grievances, track application status, search comparable sales, and manage your appeal electronically.

Nassau County Department of Assessment →

Official assessor website with property search tools, exemption applications, assessment rolls, and contact information for assessment questions.

Nassau County Property Tax Exemptions Information →

Comprehensive information and application forms for all available property tax exemptions including STAR, Senior Citizens, Veterans, and Disability exemptions.

For state-wide grievance information including New York's assessment ratio and deadlines, see our New York Property Tax Grievance Guide →

Considering professional help with your grievance? Compare pricing, coverage, and pros/cons in our Best Property Tax Grievance Services (2026) or browse side-by-side service comparisons →

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← All New York property tax grievance info

Sources: https://www.nassaucountyny.gov/1510/Assessment-Review-Commission | https://www.nassaucountyny.gov/1501/Assessment | https://www.appealdesk.com/appeals/new-york/nassau | https://www.tax-rates.org/new_york/nassau_county_property_tax | https://www.cutmytaxes.com/nassau-county-grievance-deadline-is-set-for-march-31-2026/ | https://www.nassaucountyny.gov/3575/Exemption-Applications-Forms-PDF

Last verified: 2026-07-24