Nassau County, New York

Filing deadline: March 1 (earliest possible)
The filing window (commonly called "grievance") for an application for correction of assessment normally runs from early January through March 1 each year, based on that year's tentative assessment roll, filed online through the Assessment Review Commission's AROW system. Nassau County has extended this filing window in past years. Confirm the current cycle's exact dates on the Assessment Review Commission's own site before relying on March 1.

What to file

grievance

Approximate effective tax rate

0.71% (published estimate, 2025)

Look up your current assessed value on the county assessor's site →

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