How do I grieve my Nassau County assessment through ARC and AROW?

Nassau County is a county-wide assessing unit and runs its own grievance system through the Assessment Review Commission (ARC) — it does not use town Boards of Assessment Review or the standard fourth-Tuesday-in-May Grievance Day.

File through AROW. ARC's online filing system is AROW (Assessment Review on the Web), at nassaucountyny.gov/4650/AROW. Filing online is free and lets you track your application status and receive determinations electronically. There is no filing fee to grieve to ARC.

The deadline. Nassau's grievance window opens when the tentative roll is published in early January and closes about two months later. For the 2027/28 assessment (published on the January 2, 2026 roll), the filing period ran January 2, 2026 through March 2, 2026 — March 2, 2026 was the last day to appeal. See How to Appeal Your Assessment and the ARC home page. Confirm each year's exact dates with ARC, as the county occasionally extends the deadline.

Why Nassau is different. Because Nassau assesses years ahead (the roll you grieve is for a future tax year), the timing is unusual relative to the rest of New York. ARC reviews the Department of Assessment's tentative value; it can offer a reduction or deny the claim.

If ARC denies you. As with the rest of the state, the judicial follow-on for an owner-occupied 1-3 family home is SCAR under RPTL §730 (a $30 petition filed within 30 days of the final roll), or an Article 7 proceeding for other property. You must have filed the ARC grievance first.

Contact ARC at (516) 571-3214 or ARC@nassaucountyny.gov for help.