If the exemption was previously granted and you no longer qualify for the exemption, the law requires that you notify the Assessor's Office as soon as possible. To claim the exemption, the homeowner must make a one-time filing with the county assessor where the property is located.Complete form BOE-266, Claim for Homeowners'. Property Tax Exemption. If you believe your property is exempt from the Rent Adjustment Program, you may get a Certificate of Exemption. Submit exemption application as soon as possible. Claim for Homeowners' Property Tax Exemption, BOE-266, DOWNLOAD. Construction or reconstruction must be substantially complete before January 1st of the year in which the reduction is requested. Sign up online or download and mail in your application. Vaccinate NY. Get the facts about the COVID-19 vaccine.