Exemptions can reduce the taxable value of the property. You may file up to 4 exemptions.The Cook County Assessor's Office has adjusted their 2022 Exemption Application mailing timeline as follows. In the event of a sale of homestead property, the homestead exemption shall remain in effect for the remainder of the assessment year of the sale. Assessments, under Illinois law, should fairly reflect market values. Exemptions for seniors are available to all homeowners born in, or prior to 1954. Property tax exemptions are savings that contribute to lowering a homeowner's property tax bill.