Tentative 2020 Cook County Equalization Factor Set

The Illinois Department of Revenue announced a tentative 2020 Cook County Equalization Factor of 3.0861 on January 26, 2021.  Every year, the Illinois Department of Revenue is legally required to calculate the equalization factor to achieve uniform property assessments throughout the state.

The Cook County Equalization Factor or multiplier is a 5.51% increase from the 2019 Cook County Equalization Factor of 2.916.  The final Cook County Equalization will be set closer to the issuance of the second installment bill which will occur in late spring or the summer of 2021.  In this press release issued by the Illinois Department of Revenue, the average three-year level of assessment is 8.33% for Class 2 (residential) properties, 7.29% for Class 3 (apartment) properties, 23.61% for Class 5a (commercial) properties and 26.35% for Class 5b (industrial) properties.  The three-year average level of assessments (weighted by class) for Cook County property is 10.80%.

If the median level of assessment for all property in the county varies from the 33 1/3 percent level of assessment required by law, an equalization factor is assigned to bring assessment to the legally mandated level by the Illinois Property Tax Code.