Find the Parcel, Read the Assessment, and Know What to Do Next
Nassau County’s Land Records Viewer can show far more than an assessed value. A parcel record can connect you with Section-Block-Lot identifiers, market value, assessment history, tax class, school and general tax information, property descriptions, exemptions, recent sales, maps and prior notices.
This guide explains exactly how to search, what every important field means, how to fix a failed address search, which assessment year you should read in 2026, when AROW is the correct next step, and which office handles taxes, exemptions, maps or assessment corrections.
Quick answer: use Nassau’s Land Records Viewer first
Open the official Nassau County Land Records Viewer, search by property address or Section-Block-Lot, open the correct parcel, then verify the address, municipality, school district and S/B/L before relying on any value or tax information. From the parcel page, use the Values, General and School Taxes, Open and Paid Taxes, Property Description, Recent Sales, Tax Maps and correspondence/notices sections as needed.
Current Nassau assessment facts
*The Class 1 limitation generally excludes value added by new construction or renovations. Always read the current parcel and county guidance because property class and circumstances matter.
Choose the property task you need to finish
Nassau property information is split among several tools and offices. Jump directly to the task that matches your question.
Search Nassau County assessment records correctly
The Land Records Viewer is the main county tool for public parcel and assessment information. You can reach it through Nassau County’s Assessment e-Services or open the viewer directly.
Search by property address
If the address search returns nothing, simplify the street
Nassau’s AROW property-search instructions contain unusually useful local search guidance. The same approach is helpful when an exact address format fails.
What you can find after opening a Nassau parcel
Record area |
What it tells you |
Best practical use |
|---|---|---|
Address |
Physical property location in the county record. |
First identity check before using values or taxes. |
Town / Village |
Municipal context associated with the parcel. |
Helps route tax and local-record questions. |
School District |
School district tied to the parcel. |
Useful when reviewing school-tax information. |
Section / Block / Lot |
Nassau’s core parcel identification system. |
Best identifier when addresses are inconsistent. |
Tax Class |
Assessment classification used for the property. |
Important for understanding assessment rules and comparisons. |
Fair Market Value |
County’s indicated market-value figure for the roll year. |
Compare with recent market evidence and prior years. |
Level of Assessment |
Percentage used in converting market value into assessment. |
Do not confuse this percentage with a tax rate. |
Assessed Value |
Assessment figure shown for the tax roll. |
Used in the tax-allocation process; not the same as the bill. |
Transitional Assessed Value |
Phased assessment figure shown for certain classes where applicable. |
Important for Class 2/Class 4 parcels subject to phase-in rules. |
Roll Status |
Whether the displayed assessment is tentative or final. |
Critical before comparing years or filing an appeal. |
General / School Taxes |
Tax information associated with the parcel. |
Research tax history and tax-year relationships. |
Open / Paid Taxes |
Tax status information available through the viewer. |
Useful research clue, but verify a live balance with the collecting office before paying. |
Recent Sales |
Recorded sales associated with the parcel and surrounding assessment research. |
Useful when reviewing market value or preparing an appeal. |
Property Description |
Land/property-classification and descriptive details. |
Check for incorrect use, dimensions, building type or classification. |
Tax Maps |
County tax-map material for the parcel area. |
Locate the tax lot; do not treat it as a boundary survey. |
Notices / Correspondence |
Available tentative-value, tax-impact or other assessment notices. |
Compare what the county communicated for different roll years. |
Market value, assessed value and tax bill are three different numbers
Assessment does not equal tax
Nassau County determines property assessment values. The eventual tax bill also depends on budgets, tax levies, taxing districts, exemptions and applicable rates.
A lower assessed value can affect the property’s share of the tax levy, but it does not mean the tax bill drops by the same percentage.
Read the calculation in this order
Choose the right Nassau County assessment year
Nassau assessment records display multiple roll years. As of September 2026, the 2026/27 assessment roll is final while the 2027/28 assessment is still in the tentative/review cycle.
Assessment cycle |
Tentative roll |
ARC filing period |
Final roll |
Tax bills tied to roll |
|---|---|---|---|---|
2027/28 |
January 2, 2026 |
Original calendar began Jan. 2, 2026; county materials later reflected an extension through March 31, 2026. The filing window is now closed. |
April 1, 2027 |
School bill Oct. 2027; general bill Jan. 2028. |
2028/29 |
January 4, 2027 |
January 4–March 1, 2027 |
April 3, 2028 |
School bill Oct. 2028; general bill Jan. 2029. |
The Land Records Viewer shows tax information—but it is not the universal payment office
Nassau property-tax responsibilities are split. The Department of Assessment determines assessment information; town or city tax receivers generally handle current school/general collections for their jurisdiction; the Nassau County Treasurer handles delinquent taxes after the local collection period moves to the county.
Assessed value
Tax class
Current general
Tax payment
Arrears
County collection
Value review
Classification
Tax map
Certified records
How to research a tax bill from the parcel page
If the assessment is wrong, use AROW—not the tax-payment portal
The Nassau County Assessment Review Commission (ARC) is separate from the Department of Assessment. ARC reviews timely Applications for Correction of Assessment. Its online system is AROW—Assessment Review on the Web.
What to do when the next AROW window opens
Which ARC form matches the issue?
Form |
Use it for |
Typical example |
|---|---|---|
AR1 |
Value challenge for an exclusively residential one-, two- or three-family home or eligible Class 1 condominium. |
You believe the county’s market value for your single-family home is too high. |
AR2 |
Value challenges for other property types. |
Commercial, industrial, apartment or another property not handled by AR1. |
AR3 |
Classification, exemption or another non-value assessment issue. |
Wrong tax class or denied exemption. |
Use Nassau’s AROW Sales Locator carefully
Nassau’s AROW Sales Locator can help residential owners research comparable sales, but it is a research tool rather than an appraisal.
Filter |
Initial criterion |
Why it matters |
|---|---|---|
Sale validity |
Recorded by Department of Assessment as a valid sale |
Removes transactions not treated as ordinary comparable sales. |
Distance |
Within approximately 0.35 miles initially |
Keeps the first comparison set geographically close. |
Building size |
Within 20% of subject building square footage initially |
Reduces major size differences. |
Sale timing |
Within 12 months of taxable-status date initially |
Focuses on sales closer to the valuation date. |
Land size |
Within 30% of subject land footage initially |
Avoids comparing substantially different sites. |
Selected comparables |
Maximum of five sales can be selected |
Encourages a focused comparison set. |
Check exemptions separately from market value
Exemptions can change taxable value even when the Department of Assessment’s underlying market-value opinion remains unchanged.
Before applying
Use S/B/L for tax-map verification and parcel-map requests
Nassau County’s Tax Map & Apportionment unit handles tax-map verification, maps, parcel groupings, splits and related records. The most useful identifier is usually Section, Block and Lot.
Tax Map Verification Letter
Record/service |
Current published fee |
Practical note |
|---|---|---|
Tax Map Verification Letter |
$270 per letter |
Verify live fee immediately before ordering. |
Block Map (18 × 24) |
$10 |
Tax-map reference, not a boundary survey. |
Section Map |
$5 |
County tax-map material. |
Sheet Map |
$5 |
Check current page for updates. |
Certified Map |
$15 |
Different from an ordinary map copy. |
RP-5217 Report |
$4 |
Use exact parcel/property reference. |
Call the office that controls the problem
Office |
Use it for |
Contact |
Do not use it for |
|---|---|---|---|
Department of Assessment |
Parcel record, market value, assessed value, property inventory, exemptions, tax class, tax maps. |
240 Old Country Rd., 4th Floor, Mineola, NY 11501 · 516-571-1500 · Mon–Fri 8:00 a.m.–4:30 p.m. |
Paying a current property-tax installment. |
Assessment Review Commission |
Administrative grievance/application for correction of assessment. |
240 Old Country Rd., 5th Floor, Mineola, NY 11501 · 516-571-3214 · ARC@nassaucountyny.gov · Mon–Fri 9:00 a.m.–4:30 p.m. |
Changing tax rates or paying a bill. |
Town / City Receiver of Taxes |
Current school/general tax bill, installment, receipt and payment. |
Depends on municipality. |
Changing Nassau’s assessment value. |
Nassau County Treasurer |
Delinquent taxes after collection transfers to the county. |
1 West Street, Mineola, NY 11501 · 516-571-2090. |
Assessment grievances. |
Fix the specific Nassau property-record problem
Before relying on a Nassau assessment record
More CountyAuditors.org property-record help
New York does not use the same county-auditor property structure found in states such as Ohio or Indiana. The task-first office model is more reliable: assessor/assessment office for value, receiver/treasurer for taxes and the recording office for deeds.
Nassau County tax assessment FAQs
How do I search a Nassau County property assessment by address?
Open Nassau County’s Land Records Viewer and start with the physical property address. If the exact address fails, simplify the street name by removing directional prefixes and street suffixes. Open the candidate parcel and verify its Section, Block and Lot before using the assessment information.
What is Section, Block and Lot in Nassau County?
Section, Block and Lot—often shortened to S/B/L—is Nassau County’s core tax-map parcel identifier. It is more precise than an owner name and is especially useful when an address is entered differently across records.
What information does the Nassau County Land Records Viewer show?
Depending on the parcel, the viewer can show assessment values, tax class, Section-Block-Lot, school and general tax information, open and paid taxes, property descriptions, recent sales, tax maps, property photographs, exemptions and assessment notices or correspondence.
Is Nassau County assessed value the same as the property-tax bill?
No. The Department of Assessment determines assessment information. The final tax bill also depends on tax levies, budgets, taxing districts, applicable rates and exemptions. A lower assessment does not automatically produce an identical percentage reduction in the bill.
Which Nassau County assessment roll should I use in 2026?
The 2026/27 roll is final as of April 1, 2026. The 2027/28 assessment is tentative as of January 2, 2026 and is scheduled to become final on April 1, 2027. Choose the roll year that matches the tax or appeal question you are researching.
When is the next Nassau County property assessment appeal period?
The next published ARC filing period is January 4 through March 1, 2027 for the 2028/29 tentative assessment. The filing period for the 2027/28 assessment occurred in 2026 and is closed.
What is AROW in Nassau County?
AROW means Assessment Review on the Web. It is the Nassau County Assessment Review Commission’s online system for filing and tracking assessment appeals and accessing assessment-review information. Registration is required to file an appeal.
What is the difference between AR1, AR2 and AR3?
AR1 is generally used for value challenges involving qualifying one-, two- or three-family residential property and eligible Class 1 condominiums. AR2 is used for other property types. AR3 is used for classification, exemption and other non-value assessment issues.
How much is a Nassau County Tax Map Verification Letter?
Nassau County’s current published fee page lists a Tax Map Verification Letter at $270 per letter. An older county PDF still contains a $75 fee, so verify the amount on the live county fee page before submitting a request.
Who do I call about unpaid Nassau County property taxes?
For a current tax bill, start with the Receiver of Taxes or city tax office responsible for the property’s municipality. When the collection period has transferred delinquent taxes to Nassau County, contact the Nassau County Treasurer at 516-571-2090.

Khushboo Bobade is the editor and digital publisher of CountyAuditors.org. She oversees the research and editorial process for the website, ensuring that information about county auditor offices, property records, and government resources is accurate, verified, and easy for visitors to understand.
10 Ohio Property Tax Calculators & Auditor Tools
Built specifically for Ohio's 35% assessment ratio, current DTE forms, and 2026 Homestead, Owner-Occupancy, CAUV, Conveyance Fee, and Board of Revision rules. Every number reflects verified Ohio Department of Taxation amounts.
Annual Tax Bill Estimator
OHIOApplies Ohio's 35% assessment ratio plus your county's effective millage tier — the actual math your auditor uses.
Homestead Reduction Calculator
DTE 105A2026 Ohio Homestead: $29,000 general or $58,000 enhanced (100% disabled vet, KIA spouse). OAGI under $41,000 required for non-veteran applicants.
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DTE 105CEvery Ohio owner-occupied home qualifies for the 2.5% Owner-Occupancy Credit plus the automatic 10% Non-Business Credit. Most owners don't realize these stack.
Conveyance Fee Calculator
ORC 322When you sell or transfer Ohio property, the auditor collects $1 state + up to $3 county per $1,000, plus $0.50 per parcel. Counties choose their rate.
CAUV Agricultural Savings
DTE 109Ohio's Current Agricultural Use Value cuts taxable value dramatically for farmland (10+ acres, or smaller with $2,500+ annual gross income).
Mill Rate Converter
Ohio tax rates appear three ways on auditor sites: mills, percent, or dollars per $1,000. Convert between them instantly.
Parcel Number Cleaner
Ohio's 88 counties each format parcels differently — Franklin uses 010-123456-00, Cuyahoga uses 001-23-456, Hamilton uses 100-0001-0001-00. Auto-detects.
35% Ratio Sanity Check
Ohio law sets taxable value at 35% of market value. If yours is significantly higher, you're a strong BOR appeal candidate.
BOR Appeal Savings
DTE 1A successful Board of Revision complaint typically cuts your value 10–20%. Filing is free and stays in effect until the next reappraisal.
BOR Deadline Countdown
MAR 31Ohio's statutory Board of Revision filing deadline is March 31 for the prior tax year. Miss it and you wait until next year — no extensions.
Verify with the official Ohio source
These calculators use the verified 2026 Ohio Department of Taxation amounts and statutory rules. For your exact bill, exemption status, and county-specific deadlines, always confirm with your county auditor and the Ohio Revised Code:
Estimates use Ohio's 35% statutory assessment ratio and effective tax rate tiers averaged across major Ohio counties. Your actual bill depends on local school levies, voted millage, inside vs. outside millage splits, House Bill 920 reduction factors (HB 920), and special assessments. The 2026 Homestead general amount ($29,000) and enhanced amount ($58,000) reflect HB 187 inflation indexing — your county auditor's office may show slightly different transitional figures. Nothing here is legal or tax advice. CountyAuditors.org is an independent informational directory, not affiliated with any county government.