Deadlines & how it works
How often is my property reassessed in Cook County?
Once every three years. Cook County reassesses on a triennial rotation across three groups — the City of Chicago, the north and northwest suburbs, and the south and west suburbs — one group each year. Your township’s reassessment year is when your assessed value is most likely to change.
Each township page shows which group your township is in and when it was last and will next be reassessed. You can still appeal in the two off-years, but the reassessment year is the one to watch.
Check your address — freeSee your own assessment math before you file. You keep 100%.