No information is available for this page. Exemption applications must be filed with your local assessor's office.See our Municipal Profiles for your local assessor's mailing address. Online Homestead Exemption filing for tax year 2025 is open. The deadline to file any exemptions for the 2025 tax year is March 1, 2025. The deadline for filing an exemption with the Nassau County Department of Assessment is January 2nd. For all of the abovelisted exemptions, you can fill out and submit a Nassau County exemption form today! File a Tax Grievance. Senior citizens must file an application each year in order to keep the exemption. You can get information about your property tax benefits, including: Application status, Current benefit amounts, Proposed benefit for the upcoming tax year.