The Assessor's Office is available to assist you in any way possible with their assessment policies and procedures. Please note the following important dates:

• Finalization of the Tentative Assessment Roll – On or before May 1, 2025.
• GRIEVANCE DAY – Tuesday, May 20, 2025:

  9:00 am - 11:00 am | 2:00 pm - 4:00 pm | 7:00 pm - 9:00 pm

• Finalization of the Final Assessment Roll – On or about July 1, 2025.

Change in Assessment Notices

On or before May 1, 2025, our office will mail change in assessment notices for all properties that experienced an increase or decrease in assessment. Our staff is available to answer all inquiries pertaining to such notices.

Publication and Inspection of the Tentative Assessment Roll

The Tentative Assessment Roll will be finalized on or before May 1, 2025, and will be available for inspection on this website. An individual property search is also available to check the assessment of a specific property. Inspection of the Tentative Assessment Roll will be available in the Assessor’s Office located at 40 Nassau Avenue as follows:

• May 1–May 16, 2025 — 8:30 A.M.-5:00 P.M. (Monday–Friday)
• May 17, 2025 — 9:00 A.M.-1:00 P.M.
• May 19, 2025 — 8:30 A.M.-8:00 P.M.
• May 20, 2025 — 8:30 A.M.-9:00 P.M.

Filing of Grievance Complaints

Should you wish to challenge your assessment, you may file a Grievance Complaint with the Assessor’s Office as soon as the Tentative Assessment Roll is finalized. Any Grievance Complaint that is not received by the Assessor’s Office by 9:00 p.m. on Grievance Day, Tuesday, May 20, 2025, will be dismissed by the Board of Assessment Review (BAR) as untimely.

If the person or entity filing a Grievance Complaint is a Town of Islip Employee or their family member, please click here for the additional Disclosure Form that is required pursuant to Chapter 14 of the Islip Town Code.

Hand deliver your Grievance Complaint to Suite 3 of the Assessor's Office located at 40 Nassau Avenue, Islip, New York. Please see Publication and Inspection of the Tentative Assessment Roll above for dates, times, and requirements.

Grievance Day Hearings

On Grievance Day, May 20, 2025, the Board of Assessment Review (BAR) will meet to hear any complaints in the Office of Economic Development Conference Room at 40 Nassau Avenue, New York. All Grievance Complaints will be reviewed in detail by the BAR — appearance by the taxpayer is not required to file a Grievance Complaint or to have it reviewed. All taxpayers who wish to be heard on their Grievance Complaint may appear in person during the following times:

• 9:00 a.m. to 11:00 a.m.
• 2:00 p.m. to 4:00 p.m.
• 7:00 p.m. to 9:00 p.m.

If you wish to be heard on your Grievance Complaint in person, you must sign-in with your full name, Complaint No. (obtained from the Assessor’s Office when you filed your Grievance Complaint), physical property address, and contact information.

Board of Assessment Review Determinations

On or about July 1, 2025, the BAR will issue determination letters for all Grievance Complaints. All determinations will be sent via regular mail.

General Information

Informal Assessment Review

Please keep in mind, not only is our staff available to answer your assessment and exemption inquiries, our office is available for informal assessment reviews prior to March 1st of any tax year, well in advance of Grievance Day. The Assessor must value real property as of July 1st of the year prior to Grievance Day. The Assessor must also value the real property in its condition and use as of March 1st immediately prior to Grievance Day. Upon written request, if the property owner wishes to share sufficient proof of the market value of their property, our office will consider such proof prior to setting the tentative assessment for the property for the upcoming tax year. For example, an appraisal prepared for refinancing purposes and a valuation date within one year of the July 1st valuation date may be useful in a request for an informal assessment review. Likewise, an "arm's-length" sale of the subject property close to the July 1st valuation date may suggest a lower assessment.

Assessment Estimates

Upon written request, our office also provides property owners with assessment estimates, in advance of a property owner adding inventory to their real property (e.g., adding an in-ground pool, a bathroom or an addition). Such assessment estimate request forms are available for residential and commercial properties. The assessment estimate is good for one year, and is valid for the improvements contained in the assessment estimate form.

We look forward to assisting you.

Visit the Assessor's Office homepage at https://islipny.gov/departments/assessor for more information.

On October 18, 2022, the Town of Islip Town Board embraced our most vulnerable low income Senior Citizens and Persons with Disabilities by increasing the maximum income eligibility levels from $29,000 to $50,000 for qualified applicants to receive a 50% real property exemption on their Town of Islip portion of their tax bill. Now, both exemptions provide a sliding scale of exemption percentages for incomes up to $58,400, instead of the previous $37,400. If eligible, you must file a Senior Citizen Exemption application FORM RP-467 (see “RP-467 Instructions”), or Persons with Disabilities Exemption application FORM RP-459-c, together with certain proof including your 2022 income*, with the Assessor’s Offices NO LATER than Friday, MARCH 1, 2024.

* Income, in part, includes salary or earnings, net rental income, and income reportable on 1099’s - social security benefits, pension & annuities, and investment interest and dividends. Persons with Disabilities may submit 2021 or 2022 income. To see if your income qualifies, use the worksheet.

SENIOR CITIZEN EXEMPTION SUMMARY:

WHO MAY be eligible for the upcoming 2024/25 tax year:

• You own your primary residence;
• At least one spouse, or sibling owner will be 65 as of December 31, 2024, otherwise all owners must satisfy the age requirement or qualify as a person with disabilities (see below);
• The combined 2022 income of all property owners does not exceed $58,400 (title in one spouse still requires combined income unless there is a legal separation).

Review the detailed criteria and RP-467 Instructions. To see if your income qualifies, use the worksheet.

The Senior Citizen Exemption must be annually renewed prior to March 1st of each tax year, by filing a renewal application and proof of income (RP-467-Renewal).

Note, Senior Citizens who qualify for the Senior Citizen Exemption, who receive the Basic STAR Exemption, should file an Enhanced STAR application (RP-425-E) and Enhanced Income Verification Program (IVP) application (RP-425-IVP) with our STAR Office prior to the March 1, 2024 deadline. Once enrolled in the Enhanced STAR IVP program through our STAR Office, future eligibility notifications and requests will come directly from the State.



Senior Citizens must submit all applications no later than March 1, 2024 to:
Assessor’s STAR Office
40 Nassau Avenue, Suite 2
Islip, New York 11751
STAR Phone: (631) 224-5058

PERSONS WITH DISABILITIES EXEMPTION SUMMARY:


WHO MAY be eligible for the upcoming 2024/25 tax year:

• You own your primary residence;
• At least one spouse, or sibling owner is a person with disabilities, otherwise all owners must qualify as persons with disabilities or be 65 as of December 31, 2024;
• Proof of a disability;**and
• The combined 2022 income of all property owners does not exceed $58,400 (title in one spouse still requires combined income unless there is a legal separation).

**Proof of disability: award letters from Social Security Administration, Railroad Retirement Board, United States Postal Service, United States Department of Veterans Affairs, or certificate from the New York State Commission for the Blind.

Review the detailed criteria and instructions (FORM RP-459-c). (Note, the State’s instructions include the prior income limits not the limits up to $58,400). To see if your income qualifies, use the worksheet.

The Persons with Disabilities Exemption must be annually renewed prior to March 1st of each tax year, by filing a renewal application and proof of income.



Persons with Disabilities must submit applications no later than March 1, 2024 to:
Assessor’s Office
40 Nassau Avenue, Suite 3
Islip, New York 11751
Phone: (631) 224-5585

    STAR Exemptions: (two types)

Basic STAR - Available for owner-occupied, primary residences where the resident owners' and their spouses income is less than $250,000. The first $30,000 of the full value of a home is exempt from school taxes.

Enhanced STAR - Provides an increased benefit for the primary residences of senior citizens (age 65 and older) with qualifying incomes of less than $107,300 for the 2025-26 tax year. The full value exemption amount for 2025-26 school year will be determined in October 2024.

STAR exemptions apply only to school district taxes. They don't apply to property taxes for other purposes, such as county, town, village or library.

  Please note the STAR Program changes *

As a result of recent law changes, some homeowners will receive a STAR check directly from New York State instead of receiving a school property tax exemption. The amount of your benefit will be the same regardless of how you receive it. 

Beginning with the 2016-2017 school year, new STAR applicants, to receive a STAR credit check, will need to register with the New York State Department of Taxation and Finance (NYSDTF) at www.tax.ny.gov/star.

Current STAR exemption recipients

• Current Basic and Enhanced STAR exemption recipients will keep their exemption, as long as they continue to own their current home.

• New York State requires ALL NEW Enhanced STAR exemption recipients to register with New York State’s MANDATORY Income Verification Program (IVP).

*New Enhanced STAR exemption recipients must now file with the assessor the following:

• Application for Enhanced STAR Exemption – RP-425-E;
• Application for the Enhanced STAR Income Verification Program – Form RP-425-IVP (include Social Security numbers of all owners and owner’s spouse who reside on the premises); and
• Copy of your 2023 Federal or New York State income tax return, or if you were not required to file a 2023 income tax return Income for STAR Purposes Worksheet - Form RP-425-Wkst.
• Proof of Age (driver’s license) and copy of Utility Bill.

Once enrolled in the State’s IVP, you will no longer renew your Enhanced STAR exemption with the assessor anually, but must comply with any requests from the New York State Department of Taxation and Finance (NYSDTF). NYSDTF will notify you directly whether your income is below the Enhanced STAR limit.

*New Low Income Senior Citizens exemption recipients who are BASIC STAR exemption recipients, MUST now register with New York State’s MANDATORY Income Verification Program (IVP) in order to continue obtaining the Enhanced STAR exemption. File with the assessor your Low Income Senior application – Form RP 467, together with the following:

• Application for Enhanced STAR Exemption – RP-425-E;
• Application for the Enhanced STAR Income Verification Program – Form RP-425-IVP (include Social Security numbers of all owners and owner’s spouse who reside on the premises); and
• Copy of your 2023 1040 Federal (including all schedules) and New York State IT-201 income tax return, or if you were not required to file a 2023 income tax return, submit all 1099’s and the Income for STAR Purposes Worksheet – Form RP425-Wkst
• Proof of Age (driver’s license or non photo ID) and copy of Utility Bill.

Once enrolled in the State’s IVP, you will no longer renew your Enhanced STAR exemption with the assessor annually, but must comply with any requests from the New York State Department of Taxation and Finance (NYSDTF). NYSDTF will notify you directly whether your income is below the Enhanced STAR limit. YOU MUST, however, continue to renew your Low Income Senior Exemption with the Assessor annually by filing FORM RP-467-Renewal with proof of annual income.

* The New York State Department of Taxation and Finance has developed a web based registration application, and phone registration for the STAR Check program.  
To register or to ask questions please contact the State at (518) 457-2036 or online at www.tax.ny.gov/star. 

School Tax Relief (STAR) Credit: View in ENGLISH | View in SPANISH