Nassau County, N.Y.
Nassau County property tax glossary
The words on your assessment, your tax bill, and the County’s appeal pages, defined briefly and linked to the guide that explains each one in context.
These are plain-language summaries, not legal definitions. Where a term has an official meaning, we follow Nassau County’s own wording, from its assessment FAQ and glossary of assessment terms. Confirm anything you rely on with the County.
A
Adjusted market value
For a Class 1 property, the County’s market value as adjusted by the limit on assessment increases. The County suggests deciding whether to appeal by comparing this figure with your own estimate of your home’s current market value. Understanding your assessment.
Aggrieved party
A person entitled to appeal an assessment. The County lists the owner or one of the owners, a lessee of an entire property who pays all the taxes, and a buyer with a signed contract (a contract vendee, who does not qualify if the sale does not close), among others; anyone signing a representative’s authorization certifies that they are an aggrieved party or act for one. Choosing a grievance company.
Application for Correction of Assessment
The formal name for an appeal filed with the Assessment Review Commission. You file it during the published filing window, online through AROW or on one of ARC’s application forms. Filing online with ARC.
AR1, AR2, and AR3
ARC’s three application forms. AR1 contests the value of an exclusively residential one, two, or three-family house or Class 1 condominium unit; AR2 contests the value of all other property; AR3 is for disagreements about a property’s tax class or exemptions. County forms and instructions.
Arm’s-length sale
A sale on the open market, freely negotiated without undue pressure on either the buyer or the seller. A sale between relatives or a forced sale may not reflect market value, which makes it weak evidence in an appeal. Choosing comparable sales.
AROW (Assessment Review on the Web)
ARC’s free online system for filing an appeal, tracking its status, and searching residential sales. You must register to file, and the County recommends filing online over paper. Filing online with ARC.
Assessed value
The dollar figure the tax rate is applied to. In Nassau County it is the County’s estimate of market value multiplied by a fractional level of assessment, so it is much smaller than a sale price and is not an estimate of what your home is worth. Understanding your assessment.
Assessment cap
The limit on increases for Class 1 residential property: the County states its total assessed value may not rise more than 6% in one year or 20% over five years. The limit does not apply to value added by construction or renovation. Checking the tentative roll.
Assessment Review Commission (ARC)
The Nassau County agency, independent of the Department of Assessment, that reviews appeals of County assessments. The County states that ARC will either reduce an assessment or leave it unchanged, and will never increase it. How the process works.
B
Board of Assessment Review (BAR)
The local board that hears grievances where a village or city sets its own assessment. In Nassau County, an assessment by a village, the City of Long Beach, or the City of Glen Cove is appealed to that municipality’s board, not to ARC. Village tax grievances.
C
Comparable sale
A recent sale of a property similar enough to yours that its price, adjusted for the differences, indicates your home’s market value. Comparable sales are the usual evidence in a residential appeal. Choosing comparable sales.
Contingency fee
A representative’s fee that depends on the result, usually a percentage of the first year’s tax savings. Many such agreements charge nothing if there is no reduction, but that is a term to confirm in the agreement rather than assume. What a grievance costs.
D
Duplicate application
A second appeal of the same property for the same year, for example by the owner and a representative, or by two representatives. The County states that unresolved duplicate applications will be denied. Choosing a grievance company.
E
Enhanced STAR
The larger form of New York State’s School Tax Relief benefit, for homeowners who meet an age requirement and a State income limit. The State sets the thresholds and revises them between benefit years. Exemptions and STAR.
Equalization rate
New York State’s measure of a municipality’s level of assessment: its total assessed value divided by its total market value. It is used to distribute taxes fairly among municipalities that assess at different levels, not to value an individual home. Level of assessment.
Exemption
A reduction in the assessed value that is taxed, granted because of who owns or uses the property, such as age, income, disability, or military or volunteer service. An exemption is applied for separately and is not an assessment appeal. Exemptions and STAR.
F
Final assessment roll
The roll the tax bills are calculated from, reflecting changes ARC ordered. Nassau County publishes it on the first business day of April in the year after the tentative roll; the final 2028–29 roll is scheduled for April 3, 2028. The grievance deadline.
Final determination
ARC’s decision on an appeal. The County states that final determinations are issued by March 31 of the year after you file, and appear on the final roll published that April. After ARC’s decision.
Flat fee
A representative’s fee set in advance that does not change with the size of any reduction. It is known up front, and it is owed even if the savings turn out to be small. What a grievance costs.
G
Grievance
The common New York term for a request to lower a property’s assessment. In Nassau County, a grievance of the County assessment is an application to the Assessment Review Commission. How the process works.
Grievance Day
The day a local Board of Assessment Review meets to hear complaints. New York State says villages that assess typically hold it on the third Tuesday of February, though dates vary; for the County assessment, ARC instead accepts applications throughout its published filing window. Village tax grievances.
L
Land Records Viewer (LRV)
The Department of Assessment’s public lookup by address or section, block, and lot. It shows assessment roll data, tax maps, property photographs, past taxes, tax rates, exemptions, and comparable sales. Open the Land Records Viewer.
Level of assessment
The fraction of market value at which assessments are set. New York allows assessments below full market value if the fraction is uniform within each tax class, and the Department of Assessment states the level on each roll. Understanding your assessment.
M
Market value
Nassau County defines it as “the most probable price at which a property would sell if offered for sale under ordinary circumstances.” For homes, the County usually estimates it by comparison with similar homes that recently sold. Understanding your assessment.
N
Notice of Tentative Assessed Value
The notice the Department of Assessment may mail with your new tentative assessment. The County states that not receiving one does not extend your time to file, so look up your assessment each January. The grievance deadline.
O
Offer of reduction
A proposed lower assessment from ARC, which you accept by signing a stipulation, an agreement to the new figure, within the time it gives. You do not have to accept, but the County states that judicial review, including SCAR, is available only if you did not stipulate to a reduction. After ARC’s decision.
R
Representative
A firm, attorney, or other person you authorize in writing to file an appeal for you. Once you designate one, the County states that ARC may speak only to the representative, and the authorization is valid for only one filing. Choosing a grievance company.
RP-524
New York State’s Complaint on Real Property Assessment, the grievance form used in most of the State. The State directs Nassau County properties to ARC’s own forms instead; for a village assessment, ask the village clerk which form it accepts. New York State grievance procedures.
S
Section, block, and lot (SBL)
The identifier Nassau County’s tax map gives each parcel. It identifies your property in County records and on a representative’s authorization, and the County notes that its Department of Assessment and County Clerk may format it differently. Look up your property.
Small Claims Assessment Review (SCAR)
An optional, inexpensive court review for owner-occupied one, two, and three-family homes and Class 1 condominium units, heard by a court-appointed referee. It is available only after an ARC application, and the referee may lower an assessment but cannot raise it. The SCAR guide.
Special district
A taxing district, separate from your school district, town, and the County, that funds a particular local service. Its taxes appear on your bill, and some exemptions, such as the County’s senior citizen exemption, do not reduce them. How your tax bill is calculated.
STAR
New York State’s School Tax Relief program, delivered either as a credit paid by check or direct deposit or as an exemption on the school tax bill. The State says new homeowners register for the credit, since the exemption is no longer available to them. Exemptions and STAR.
T
Tax certiorari
A court proceeding, brought in State Supreme Court under Article 7 of the Real Property Tax Law, to challenge an assessment after ARC. The County notes that Small Claims Assessment Review costs considerably less for homeowners who qualify. The SCAR guide.
Tax class
One of the four categories New York law requires Nassau County to assign every property. Class 1 is one, two, and three-family homes and most low-rise condominiums; Class 2 is other residential property such as apartments and co-ops; Class 3 is utility property; Class 4 is everything else, including commercial property. Understanding your assessment.
Tax rate
The amount charged per $100 of taxable assessed value. Each school district, town, the County, and each special district divides the amount it must raise by the assessed value in its area, so an ARC appeal cannot change the rate. How your tax bill is calculated.
Taxable assessed value
The assessed value after any partial exemption is subtracted. It is the figure the tax rate is multiplied by, and it can differ for school and general taxes. Exemptions and STAR.
Taxable status date
The date on which a property’s assessed value and taxable status are fixed. The County’s glossary gives it as January 2; its current calendar dates the 2028–29 tentative roll January 4, 2027, the first business day of the year. Valuation date.
Tentative assessment roll
The County’s proposed assessments, published on the first business day of January. It is the figure you appeal during the ARC filing window, and it becomes final, with any changes ARC orders, the following April. Checking the tentative roll.
Transition assessment
A phase-in of assessment increases for Class 2 and Class 4 property. The County states that increases in those classes not caused by construction or renovation are spread over five years; Class 1 homes have the assessment cap instead. Assessment cap.
V
Valuation date
The date market value is estimated as of. Nassau County uses the first business day of January in the year the tentative assessment is published, which is January 4, 2027 for the 2028–29 assessment. Choosing comparable sales.
Put the terms to work
See these figures on your own County record, then read how an appeal moves from the tentative roll to ARC’s decision.
Check my propertyHow the grievance process works · Browse all homeowner guides