Long Island property tax grievance — complete guide

Nassau and Suffolk handle property tax grievances very differently. Nassau uses a centralized Assessment Review Commission with a March deadline; Suffolk delegates to each town's Board of Assessment Review with a May deadline. Start with your county.

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Why grieve at all?

Long Island property taxes are among the highest in the United States — median bills of $11,000-$12,000/yr across both counties. Filing a grievance is the single most effective way to lower yours, and it's essentially risk-free: Boards of Assessment Review (and Nassau's ARC) cannot raise your assessment in response to a complaint. The worst case is no change.

Successful grievances typically reduce assessed value 5-15%. On a median LI home that translates to $550-$1,700/yr in ongoing savings, every year, until the next reassessment puts you back up.

Not sure if you have a case? Take our 2-minute Should I Grieve quiz — it walks through the rule-of-thumb signals (purchase price below assessment, recent comparable sales, no recent reassessment) and tells you whether filing is worth your time.

You can also sign up for free grievance-window alerts for your parcel — one email per quarter when the grievance window opens or your assessment changes, so you never miss the deadline.

Nassau towns — file with the Assessment Review Commission

Suffolk towns — file with your Town Board of Assessment Review

Helpful related pages

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Sources & citations

Last verified: 2026-05-23. Tax rules change; we re-verify each page quarterly.

Estimates and educational content only — not legal, tax, or financial advice. Verify with your county or town receiver, an attorney, or a CPA before making financial decisions.