Calculate your reduction, get your Part B and Part D responses, estimate your savings, and learn exactly how to file — all in one place. Free. No attorney needed.
Nassau County froze the assessment rolls again this year while home prices continued to rise. That means the Level of Assessment (LOA) keeps getting more inaccurate. The projected LOA for 2027/2028 is 0.00053 — meaning the county is treating assessed values as if they represent only 0.053% of a home's true market value.
When you multiply your assessed value by 1,866 (the working multiplier for this LOA), you get what the county implies your home is worth. For many homeowners, that number is wildly higher than what the home could actually sell for. That gap is what makes you over-assessed — and that's what a grievance corrects.
Even if your home seems properly assessed, you should still file. When your neighbor gets a reduction and you don't, the tax burden shifts to you. Filing protects you. There is zero risk — your assessment cannot be increased because you filed a grievance. You can only save money or stay the same.
The entire process takes about 20–30 minutes. Follow these steps in order.
Go to askarcnassau.com and click "ARROW" in the left menu, then "Register with ARC." Fill in all required fields using an email you check frequently. Create your user ID and password. Click "Complete Registration" once — then check your email (and spam folder) for a confirmation link. After confirming, log in.
After logging in, click "Sales Locator" to search for your property. Enter your house number and street name only — don't include "Street," "Ave," "Road," etc., because the system uses abbreviations. Verify that your property details (square footage, bedrooms, bathrooms) are roughly accurate.
Click "Find Sales." The system will show recently sold homes similar to yours. Use the first 5 homes that come up. This is the single most important piece of advice — using the system's first 5 results means nobody can accuse you of cherry-picking, and these homes are almost always in your neighborhood with similar size and style.
Check the boxes next to your first 5 comps, then click "Check Selected Properties" or "Continue to Submit." The system calculates adjustments and gives you a Weighted Adjusted Sale Price. That's the key number. Write it down, then enter it into the Grievance Calculator below along with your Taxable Market Value.
Enter your Parcel ID or search by address. List all co-owners (spouse, parent, etc.) — only people listed on the application can contact ARC about the appeal. Choose electronic communication so you receive offers by email (this cannot be changed after the filing period ends).
Paste the Part B number from the Grievance Calculator below. Enter it as a plain number — no dollar signs, no decimals, no commas. Double-check for extra zeros. Remember: this number is your floor. ARC cannot reduce your assessment below what you request here.
Click the pink "Display" tab to open Part D. The Grievance Calculator below generates a ready-to-paste paragraph for the "Other Facts" text box. Just copy it and paste it in — that's all you need here.
Enter the CAPTCHA (it's not case sensitive), select "Owner" from the dropdown, review everything, and click "Submit Application Form" ONCE AND ONLY ONCE.
You'll receive a confirmation email. Then you wait. Decisions typically come between September and November by email. You MUST open the email and ACCEPT the offer, or the reduction does not count. Check your spam folder regularly during that window. The reduction affects October 2027 school taxes and January 2028 county taxes.
After you've selected your top 5 comps in Sales Locator, plug these two numbers into the calculator. Everything below will auto-populate — no buttons to click.
This is your requested full market value. Enter this exact number in Part B of the AROW form. No dollar signs, no decimals, no commas — just the number.
Paste everything below into the “Other Facts” text box in Part D of your AROW application.
Look up your property taxes at lrv.nassaucountyny.gov and enter the amounts below. Check the "School Taxes" and "General Taxes" tabs on that site. Your savings will calculate automatically.
If the reduction is 5–6% or more: Accept it. You can always file again next year for an additional reduction.
If the reduction is 2–4%: Generally accept it and file again next year. Something is better than nothing, and reductions compound over time.
If denied or under 2%: Consider filing for a Second Review or SCAR (Small Claims Assessment Review) through the County Clerk's office.
You can make changes until March 2, 2026. Go to "Appeal Filing/Status/Change" → set the tax year to 2027–28 → "Search for Appeals" (leave fields empty) → click your application → make changes → click "Submit Changes" in that specific section. Never click "Submit Application" again — that creates a duplicate.
Recently Purchased (last 3 years): Your purchase price is your best evidence. In Part D, write: "I purchased my home on [date] for $[price]. At the correct LOA of .0053, my assessed value should be no higher than [purchase price × .00053]." Upload your closing papers.
Two-Family Homes: If the system doesn't show two-family comps, use one-family comps and note in Part D: "This is a two-family home. The only meaningful difference is an extra kitchen, which adds approximately $30,000 in value over comparable one-family homes."
Recent Renovation or Extension: You are not required to disclose work until a Certificate of Occupancy (CO) has been issued. File based on what the county currently has on record.
Can't Find Good Comps: If you can't find comparable homes that are the exact same style, focus on square footage, living area, and room counts instead. Professional firms face the same challenge — work with what's available.
Assessed Value (TAV) = Taxable Market Value ÷ 1,000
County's Implied FMV = TAV × 1,866
Correct Assessed Value = Comp FMV × 0.00053
Part B Value = Correct Assessed Value × 1,000
LOA = 0.00053 | Multiplier = 1,866
Use this to make sure you haven't missed anything.