When properties are reassessed, the Assessor sends out a Notice of Proposed Assessed Valuation to each property owner. The assessment notice lists the prior assessment , new proposed assessment, market value, and other important regarding the property. It is important for taxpayers to check this information carefully and file an assessment complaint if they feel they are incorrectly assessed.

The Cook County Assessor has offices conveniently located throughout suburban Cook County and a central office located in downtown Chicago. In the suburban areas, assistance is also available from local township assessors.