April 29th, 2019 - Newsday published an in-depth analysis, endorsed by several industry professionals, of the first countywide property reassessment in nearly a decade. The comprehensive study concluded that the reassessment eliminated the inaccurate and unfair wide disparities among home values that developed under the Mangano Administration. The study found the new assessments are well within every major professional standard, with experts quoted saying, “Getting much better than this is not really feasible.” For the full story, visit:

If you would like to schedule a physical inspection of your property, please send an  email to or a letter to 240 Old Country Road, 4th floor, Mineola, NY 11501.  In your correspondence with the Department of Assessment, please include the address of the property you wish to have inspected and your contact information. 

The Department of Assessment is responsible for developing fair and equitable assessments for all residential and commercial properties in Nassau County on an annual basis. Nassau County's assessment roll includes over 423,000 properties with a value of $264 billion. It is the second largest assessing entity in the State of New York after New York City.


  • Collecting and recording relevant residential, commercial, and industrial property information.
  • Validating building permits by confirming all new construction and including the new value on the next assessment roll.
  • Maintaining property records and tax maps.
  • Answering public inquiries.
  • Assisting the public through the Department's outreach program.
  • Processing applications for property tax exemption and the Basic and Enhanced STAR programs for qualifying Nassau County homeowners.