Long Island Property Tax Grievance — Nassau & Suffolk 2026

By Nitin Gadura · April 22, 2026

Long Island has some of the highest residential property taxes in the United States. Nassau County homeowners often pay $12,000–$30,000+ per year; Suffolk County is typically $9,000–$22,000+. If your assessment is even slightly off-market, you're likely overpaying — sometimes by thousands a year. The good news: both counties have structured grievance processes, and you can file yourself or hire a firm that works on contingency. Here's how it actually works in 2026.

The Two Counties — Different Rules, Different Deadlines

Nassau and Suffolk run separate assessment and grievance systems. The process for one does not apply to the other. Here's the side-by-side:

Nassau County — Step-by-Step

1. Review your Tentative Assessment

Nassau publishes the Tentative Assessment Roll each January. You'll receive a notice showing your property's "market value" (as estimated by the county), your "assessed value," and the tax class [1]. Compare:

• County's estimated market value vs. recent sold comps in your neighborhood
• Recorded square footage vs. actual
• Recorded number of bedrooms/bathrooms/stories vs. actual
• Condition of the property (is it noted as average when it's actually below average?)

2. File Form AR1 (or the applicable form) with Nassau ARC

You can file online at the Nassau ARC portal. No filing fee. Attach:

• Three to five comparable recent sales (sold, not just listed)
• Photos of condition issues if any
• Any square-footage correction documentation
• Optional: a professional appraisal (not required, but strengthens the case for high-assessment properties)

3. ARC Review

ARC reviews your filing and may: accept your proposed reduction, counter-offer a partial reduction, or deny. You typically hear back 3–9 months after filing. If approved, the Final Roll reflects the lower assessment and your school-tax and general-tax bills drop accordingly (Nassau's tax year runs October 1 to September 30 for general taxes, with school-tax bills arriving in October).

4. If Denied — SCAR or Article 7

If ARC denies, you can file a Small Claims Assessment Review (SCAR) petition for residential properties up to certain thresholds, or an Article 7 petition in NY Supreme Court for larger cases [2]. SCAR is inexpensive ($30 filing fee) and designed for homeowners without attorneys. Article 7 requires a tax-certiorari attorney.

Suffolk County — Step-by-Step

1. Know Your Town

Suffolk has 10 towns, each with its own assessor: Babylon, Brookhaven, East Hampton, Huntington, Islip, Riverhead, Shelter Island, Smithtown, Southampton, Southold. Your tax bill and grievance are handled by your town, not by the county [3].

2. Tentative Roll Published May 1

Your town publishes the Tentative Roll around May 1. Review your property's assessment against current market comps just like in Nassau.

3. File RP-524 by Grievance Day

Grievance Day is the third Tuesday in May. File NY State Form RP-524 with your town's Board of Assessment Review [4]. No filing fee. The BAR meets on or shortly after Grievance Day to review filings.

4. BAR Decision

The town BAR issues written decisions typically within 30 days of Grievance Day. If your assessment is reduced, the Final Roll (published July 1) reflects the new number. If denied, you can file SCAR within 30 days of the Final Roll publication.

Should You File Yourself or Hire a Firm?

File Yourself If:

• Your property is a single-family home with a clear over-assessment case
• You can identify 3+ solid sold comps yourself
• You have time to assemble the filing
• Your potential annual savings are under $1,500 (firms typically take 40–50% of first-year savings)

Hire a Tax Grievance Firm If:

• You don't have time or expertise to pull comps
• Your potential savings are $1,500+/year (the 50% cut still leaves meaningful savings)
• Your property is multi-family, mixed-use, or commercial (higher complexity)
• You've been denied before and want someone who knows the specific ARC or BAR members

Most LI tax grievance firms work on contingency: no reduction, no fee. They take 40–50% of the first year's tax savings if they win, and zero if they lose. This aligns incentives well. Verify any firm you hire is licensed and has a local track record.

What Kind of Reduction Can You Actually Expect?

A successful Long Island residential grievance typically yields a 5–20% reduction in assessed value. On a home with a $15,000 annual tax bill, that translates to $750–$3,000 in first-year savings, which then compounds each year the assessment stays lower. Realistically most homeowners see a modest reduction rather than a dramatic one — but compounded over 10 years of ownership, even a 10% reduction saves five figures.

STAR & Enhanced STAR — Don't Overlook

Separate from grievance, confirm your exemptions are active:

• Basic STAR: NY homeowners with income under ~$250K get a School Tax relief credit/check [5]
• Enhanced STAR: Age 65+ with income below the annual cap get a larger benefit
• Senior Citizens' Exemption: additional reduction for low-income seniors
• Veterans' Exemption: wartime service members

These apply automatically year-over-year once you qualify, but first-time applicants must file. Check tax.ny.gov/star.

Common Mistakes That Kill Grievances

1. Comparing to listings instead of sold properties. ARC and BAR only accept sold comps.
2. Using comps from outside your school district. Cross-district comps get rejected.
3. Missing the deadline. Nassau and Suffolk are strict — one day late is disqualified until next year.
4. Failing to pay your taxes during the grievance. You must keep paying while the case is pending, or you forfeit appeal rights.
5. Grieving when you're already assessed below market. If the county's estimate is below recent sold prices on your block, a grievance can trigger a reassessment upward. Do the comp math first.

Related Reading

Deadlines, forms, and procedures change. Always confirm the current year's deadline with Nassau ARC or your Suffolk town assessor before relying on dates in this article. Informational only; not legal or tax advice. Consult a NY-licensed tax-certiorari attorney for Article 7 petitions, commercial-property grievances, or any contested case involving significant dollar amounts. Nitin Gadura, Gadura Real Estate, LLC. Equal Housing Opportunity.