Nassau County Tax Assessment Search & Records (NY)

Nassau County, New York · Assessment · S/B/L · Taxes · Maps · AROW

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.

Important distinction: a Nassau County assessment record is not the same thing as a current tax bill, deed, boundary survey or proof of legal ownership. Use the Department of Assessment for parcel/value information, the correct Receiver of Taxes or Treasurer for payment questions, and the appropriate land-record office for recorded instruments.

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.

1 Find the parcel Search address or Section-Block-Lot.
2 Verify identity Match address, town, school district and S/B/L.
3 Choose the roll year Do not confuse tentative and final assessment years.
4 Route the next task Assessment, appeal, exemption, tax payment or map.

Current Nassau assessment facts

Property identifier Section / Block / Lot
2026/27 roll Final as of April 1, 2026
2027/28 roll Tentative as of January 2, 2026
2027/28 final roll Scheduled April 1, 2027
Next grievance window Jan. 4–Mar. 1, 2027
Assessment office 516-571-1500
ARC customer service 516-571-3214
Class 1 viewer LOA 0.1% on current records
Class 1 increase cap 6% yearly / 20% over 5 years*
Official parcel viewer JavaScript required for full functionality

*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.

Nassau search quirks

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.

No result for “23 North Main Street” Try the house number with Main only.
Directional prefix causes trouble Remove N, S, E or W unless the system truly needs it.
Street suffix causes trouble Remove Avenue, Street, Road, Court, Lane, Drive or similar suffixes.
Unsure of spelling Nassau’s AROW guidance suggests entering only the first few letters of the street name.
Address recently changed Search by S/B/L from an older tax bill or assessment notice.
Condo or cooperative Verify building, unit and parcel fields instead of assuming the street address identifies one tax lot.
Example from Nassau’s own search guidance: entering a partial street such as “Ches” can return possible names such as Chestnut, Chester or Chess. Start broad and let the official result list help you identify the correct street.
Record decoder

What you can find after opening a Nassau parcel

Nassau Land Records Viewer field guide
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.
Before acting on a record: verify at least four identifiers—physical address, town/village, S/B/L and assessment year. A correct owner name alone is not enough when the same person owns multiple parcels.
Assessment math

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

Find Fair Market Value This is the county’s indicated estimate of market value for that roll year.
Find Level of Assessment This is an assessment percentage—not the property’s tax rate.
Find Assessed Value Compare the figure with prior and tentative years.
Check Transitional Assessed Value when shown Class 2 and Class 4 records may show phased transitional values.
Check exemptions separately Exemptions can change taxable assessed value without changing the underlying market-value opinion.
Use the tax office for the bill The assessment record explains value; the collecting office controls the live bill and payment balance.
Current viewer examples: Nassau Class 1 parcel records currently show a 0.1% Level of Assessment, while current Class 4 examples show 1%. Do not apply a percentage from another parcel blindly—read the Level of Assessment displayed on the exact parcel and roll year you are reviewing.
Class 1 cap: Nassau’s official records and FAQ explain that Class 1 assessment increases generally cannot exceed 6% over the prior assessment or 20% over five years, excluding value attributable to new construction or renovation and subject to the applicable rules.
2026–2028 assessment calendar

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.

April 1, 2026 2026/27 Final Final assessment roll published.
January 2, 2026 2027/28 Tentative Tentative roll published for the next assessment cycle.
April 1, 2027 2027/28 Final Scheduled final-roll publication.
January 4, 2027 2028/29 Tentative Next tentative assessment roll scheduled.
Nassau County assessment-review calendar
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.
Do not wait for the tax bill to challenge a new assessment. Nassau’s administrative assessment appeal period occurs well before the taxes based on that assessment are billed.
Tax records and payments

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.

1
ASSESSMENT Market value
Assessed value
Tax class
2
RECEIVER Current school
Current general
Tax payment
3
TREASURER Delinquent taxes
Arrears
County collection
4
ARC Assessment grievance
Value review
Classification
5
MAP / RECORD S/B/L
Tax map
Certified records

How to research a tax bill from the parcel page

Open the exact parcel Verify S/B/L before opening tax information.
Open General and School Taxes Compare the tax year with the assessment-roll column being reviewed.
Check Open and Paid Taxes Use this as research information and identify whether the tax appears current or delinquent.
Identify the municipality Hempstead, North Hempstead, Oyster Bay, Glen Cove, Long Beach and incorporated villages can have different payment routing.
Open the correct tax collector before paying Verify the current balance, installment and penalties directly with the responsible receiver.
If the local warrant is closed, check Nassau County Treasurer Delinquent collections can move from the town/city receiver to the County Treasurer.
Nassau timing example: current-tax collection and delinquent-tax collection are different. The Town of Oyster Bay, for example, directed unpaid 2026 General taxes to the Nassau County Treasurer after August 31, 2026.
Nassau County Treasurer: 1 West Street, Mineola, NY 11501 · 516-571-2090. Use the Treasurer for delinquent-tax questions once collection has transferred to the county.
Assessment Review Commission

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.

September 2026 status: the administrative filing period for the 2027/28 tentative assessment has already closed. The next published filing window is for the 2028/29 assessment from January 4 through March 1, 2027.

What to do when the next AROW window opens

Open your Land Records Viewer parcel first Record the S/B/L, current tax class, fair market value and tentative assessed value.
Decide what is actually wrong Value problem, classification problem and exemption problem use different claim logic.
Use AROW Registration is required to file an appeal, although public sales and inquiry functions can be used without registering.
Enter the property and requested market value carefully ARC states that it will not reduce the value below the requested market value entered on the application.
Attach useful evidence AROW can accept documents such as spreadsheets, digital photographs and scanned images. Nassau states that video files are not accepted.
Save the appeal/application number Successful online transmission generates an appeal number.
Check confirmation within 48 hours If the expected confirmation email does not arrive, check spam/junk and log back into AROW to confirm an application number exists.
Track the case online Online filing lets owners monitor appeal status and respond to ARC communications.

Which ARC form matches the issue?

Nassau ARC application routing
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.
Self-filing: Nassau ARC says there is no filing fee for an owner filing for themselves, and an attorney is not required for the administrative appeal.
ARC call script “I am reviewing parcel Section [ ], Block [ ], Lot [ ]. The Land Records Viewer shows a [tentative/final] assessment of [amount] for roll year [year]. My concern is [market value / classification / exemption]. Which current AROW claim or form should I use, and what evidence should I prepare?”
Comparable sales

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.

AROW Sales Locator starting criteria
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.
Do not treat the Sales Locator’s adjusted figure as an official appraisal. ARC states that results are informational and that its valuation professionals make an independent determination.
Tax exemptions

Check exemptions separately from market value

Exemptions can change taxable value even when the Department of Assessment’s underlying market-value opinion remains unchanged.

Senior Citizen Income/age-based relief may be available subject to current eligibility rules.
Veterans Nassau administers applicable veterans-related exemption programs.
Cold War Veteran A separate local-option veterans exemption may apply where adopted.
Disability / Limited Income Qualifying homeowners may be eligible for disability-related property-tax relief.
Volunteer Fire / Ambulance Eligible volunteers may qualify under applicable local programs.
STAR STAR administration differs depending on the owner’s enrollment/history; new homeowners generally follow New York State STAR procedures.
2027/28 exemption deadline: Nassau County’s 2026 outreach notices state that exemption applications for the 2027/28 property-tax year must be received by January 4, 2027.

Before applying

Confirm the exemption name
Confirm ownership/residency requirement
Check income rules where applicable
Prepare prior-year tax returns when required
Prepare veteran/service documents where relevant
Confirm city/village filing requirement
Keep copies of submitted evidence
Verify the exemption later on the parcel record
Local Nassau wrinkle: if the property is inside an incorporated village or certain city jurisdictions, a local exemption filing can sometimes be required in addition to the Nassau County filing. Check the village/city assessor or clerk instead of assuming the county application covers every local levy.
Tax maps and official record copies

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

Find the parcel’s S/B/L first Use Land Records Viewer or a current tax bill.
Open the current Tax Map & Apportionment page Do not start from an old downloadable form found through a search engine.
Select Tax Map Verification Online Services Follow the county’s current request workflow.
Verify the live fee before paying Nassau’s current FOIL/fee page lists the Tax Map Verification Letter at $270 per letter.
Save the request/payment confirmation Keep it with the S/B/L and property address.
Old-form warning: an older Nassau County Tax Map Verification PDF still states a $75 processing fee. The county’s current fee page lists $270. Use the current live fee schedule rather than an archived form when amounts conflict.
Selected current Nassau assessment-record fees
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.
Boundary warning: a Nassau tax map helps identify the assessment parcel. It is not a substitute for a licensed boundary survey, deed review or legal title examination when a boundary or ownership dispute exists.
Office routing

Call the office that controls the problem

Nassau County property-office router
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.
Troubleshooting

Fix the specific Nassau property-record problem

Address returns no parcel Remove direction, suffix and punctuation; try only the main street word or S/B/L.
Several parcels have similar addresses Match town, school district and S/B/L before opening tax information.
Owner name looks outdated A recent transfer may not yet appear in every assessment-related field. Verify recorded ownership separately if legal title matters.
Assessment changed but tax bill did not fall Assessment is only one component of the final tax calculation; levies, rates and exemptions also matter.
2027/28 still says tentative That is expected before the scheduled April 1, 2027 final roll.
2027/28 appeal link is closed The 2026 administrative filing period has ended. Prepare for the next 2028/29 window if challenging the next tentative assessment.
Tax-map fee differs between documents Use the live Nassau fee page. Do not rely on the older $75 verification form.
Tax shows unpaid but town portal is closed Contact the Nassau County Treasurer to determine whether collection has transferred.
Property class appears wrong Review the parcel description and use the appropriate ARC non-value/classification route when the filing period is open.
Building facts are incorrect Contact the Department of Assessment and identify the exact inventory field you believe is wrong.
Need a boundary line Do not use the tax map as legal boundary proof; obtain the appropriate survey/title evidence.
Need an old roll Use Nassau’s Assessment Rolls archive rather than assuming today’s parcel screen preserves every historic figure in the same format.
Assessment-office call script “I am researching Nassau County parcel Section [ ], Block [ ], Lot [ ] at [address]. The Land Records Viewer shows [specific field/value] for roll year [year]. I believe [specific inventory/value/classification item] may be incorrect. Can you tell me which Department of Assessment record or current correction process applies?”
Buyer / owner due diligence

Before relying on a Nassau assessment record

Match physical address
Match S/B/L
Confirm town/village
Confirm school district
Check current tax class
Identify tentative vs final roll
Compare recent sales
Review property description
Check exemptions
Check open/paid tax information
Verify current tax balance before paying
Use recorded documents for legal-title questions
Internal help

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.

10 Nassau-specific answers

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.

Information checked September 2, 2026: Nassau County Land Records Viewer fields and search behavior, Department of Assessment contact information, 2026/27 and 2027/28 assessment-roll status, 2028/29 ARC filing dates, AROW procedures, ARC forms, Class 1 assessment limits, tax-map services and current record fees, exemption timing and delinquent-tax routing were checked against current Nassau County and local-government sources.
Ohio Auditor Tools · Tax Year 2026

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.

Homestead: $29,000 Enhanced Vet: $58,000 OAGI limit: $41,000 Assessment: 35% of market BOR filing: Free · DTE 1

Annual Tax Bill Estimator

OHIO

Applies Ohio's 35% assessment ratio plus your county's effective millage tier — the actual math your auditor uses.

Pick a county tier and enter your market value.

Homestead Reduction Calculator

DTE 105A

2026 Ohio Homestead: $29,000 general or $58,000 enhanced (100% disabled vet, KIA spouse). OAGI under $41,000 required for non-veteran applicants.

Pick your situation and enter your home value.

Owner-Occupancy & Non-Business Credits

DTE 105C

Every 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.

Enter your annual tax to see both credit amounts.

Conveyance Fee Calculator

ORC 322

When 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.

Enter sale price and pick your county rate.

CAUV Agricultural Savings

DTE 109

Ohio's Current Agricultural Use Value cuts taxable value dramatically for farmland (10+ acres, or smaller with $2,500+ annual gross income).

Enter both market and CAUV values to see savings.

Mill Rate Converter

Ohio tax rates appear three ways on auditor sites: mills, percent, or dollars per $1,000. Convert between them instantly.

Enter a rate to see all three forms.

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.

Paste any Ohio county parcel to format it.

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.

Enter both values to compare against Ohio's 35% target.

BOR Appeal Savings

DTE 1

A successful Board of Revision complaint typically cuts your value 10–20%. Filing is free and stays in effect until the next reappraisal.

Enter your tax bill and reduction estimate.

BOR Deadline Countdown

MAR 31

Ohio'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.

Set your deadline to start the countdown.

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.

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