Reassessment and You

Nassau County, NOT the Town of Hempstead, is responsible for setting your property tax assessment. In 2018, the Nassau County Executive ordered the reassessment of every property within the county’s jurisdiction. Being that your home’s assessment is the basis of your property taxes, the County Executive’s reassessment project could significantly impact the amount you pay in property taxes.

Using a variety of technical and algorithmic methods, the County Assessor has determined updated market values for all properties. These values will be utilized to determine your property taxes under the 2020/2021 tax roll.

By law, the assessed value of Class 1 properties may not be increased by more than 6% per year, or more than 20% within a five-year period (unless the value increases are due to renovations or new construction). The County Assessor has taken steps to circumvent the aforementioned caps on assessment increases. Indeed, reports of assessment increases in excess of 50% have been documented.

The Nassau County Assessor has sent property owners an Assessment Disclosure Notice stating the updated market value estimate and preliminary tentative assessment for properties. This information is also available online on the Nassau County Department of Assessment's Land Records Viewer at (enter parcel number or property address, click on "View Correspondence," and select “511 Notice”). In addition, the Assessor has issued “Tax Impact Notices” to residential property owners. The notices, which are viewable on mynassauproperty.comprovide a comparison of your 2017/18 actual taxes to a hypothetical application of those same taxes using your preliminary assessments for 2020/2021.

If you disagree with your preliminary tentative assessment, you may schedule a one-on-one appointment with Assessment Department staff through the end of January 2019 by calling the Assessment Office at (516) 571-4374 or by visiting the county’s assessment website ( If the Department of Assessment determines that revisions are warranted based upon information owners present at their assessment review appointment, the market value estimates may be adjusted.

On January 2, 2019 the Department of Assessment will publish the tentative assessment roll based on value as of this date. The formal period to appeal published 2020/2021 tentative assessments begins.

Challenge and Lower Your Taxes

If an owner believes that his/her property tax assessment is not accurate, an Application for Correction of Assessment may be filed with the Nassau County Assessment Review Commission (ARC). However, to date, Nassau County has not disclosed how its assessment changes would impact the assessment review process.

The deadline to file a property assessment grievance has been extended from March 1, 2019 to April 30, 2019. You may file an Application for Correction of Assessment online at AROW (Assessment Review on the Web) or in person at the Assessment Review Commission (ARC) located at 240 Old Country Road in Mineola. You may also request that an Application for Correction of Assessment be mailed to you by calling ARC at (516) 571-3214.

When challenging your assessment, it is important to build the best case for lowering your assessment by providing data on comparable properties. Use the ARC’s online residential appeal system (AROW-Assessment Review on the Web) sales locator tool to view recent sales of similar homes in your neighborhood and file an application to correct your property’s assessment.

Remember, there is no charge for filing an assessment challenge, and assessments can only be lowered or remain the same as a result of a challenge, they cannot be raised.

How to Challenge

Filing Period: The deadline to file an appeal to challenge your property’s assessment has been extended from March 1, 2019 to April 30, 2019.

Online: Application for Correction of Assessment forms will be available online from the Assessment Review Commission website after January 2nd. Applications may be filed electronically through AROW (Assessment Review on the Web) through April 30, 2019 with the same effect as filing on paper. Successful transmissions generate an appeal number immediately and an e-mail message after a short delay.

By Phone: You may request that an Application for Correction of Assessment form be mailed to you by calling the Assessment Review Commission at (516) 571-3214.

In-Person: Application for Correction of Assessment forms may be obtained and submitted in person at 240 Old Country Road, Mineola, NY 11501, from 9:00 AM to 4:30 PM, Monday to Friday, except holidays.

By Mail: Applications can be mailed to the Assessment Review Commission at 240 Old Country Road, Mineola, NY 11501. Mail must be postmarked by the USPS, or a private carrier designated by the IRS, no later than 11:59 PM on April 30, 2019.

Small Claims Assessment Review

The Assessment Review Commission is responsible for reviewing assessed valuations and making decisions on grievances during this period. Owners who are not satisfied with the Assessment Review Commission's decision have the option to file a Small Claims Assessment Review (SCAR) petition to seek further review of their assessment.

Incorporated Villages

Incorporated villages within the Town of Hempstead have the right to utilize their own assessments for village tax purposes, or they may choose to utilize the county's assessment roll as a basis for their assessments. If you live in an incorporated village, you must file separately to challenge your village assessment. Contact your village Assessor for information on how to challenge that assessment.