Cook County, Illinois

Cook County has no single filing deadline. Each township has its own Assessor appeal window, which opens when that township's Reassessment Notice is mailed and closes about 43 days later. A separate Board of Review appeal window of about 30 days opens later for each township. Cook County reassesses on a three-year cycle: the City of Chicago in 2024 (next 2027), the north and northwest suburbs in 2025, and the south and west suburbs in 2026. Most properties receive no new notice in a given year. Find your township on the Assessor's calendar.