Recently, the Illinois Department of Revenue released the final 2009 Cook County equalization factor. The 2009 equalization factor, 3.3701, is approximately 13% higher than the 2008 equalization factor of 2.9786. Cook County assesses property taxes in arrears, which means the 2009 equalization factor is used to calculate 2009 property taxes which are paid in two installments in 2010. The first installment of the 2009 Cook County property taxes, paid in spring 2010, was equal to 55% of the 2008 property taxes, which were paid in 2009. The 2010 second installment is the difference between the actual amount of the 2009 property taxes and the amount of the first installment.
An equalization factor is used to ensure that each county in Illinois assesses real property at 33 1/3% of fair market value. Because real property is traditionally assessed lower in Cook County as compared to other counties in the State, Cook County’s equalization factor tends to be higher than the equalization factor in other counties. For example, Kane County, a neighboring county to Cook County, has consistently had an equalization factor of 1.0000 for the past 22 years.
While the Cook County equalization factor has increased, it is only one of several variables that ultimately determine the amount of property tax levied on each parcel of real property in the County. This is especially true this year because the 2009 assessment percentage in Cook County for residential properties has been reduced from 16% to 10% of fair market value and the 2009 assessment percentage for commercial and industrial properties has been reduced from 38% and 36% respectively to 25% of fair market value. This change in assessment percentage could also alter the distribution of the tax burden on different types of property. As a result, the full impact of the 2009 Cook County equalization factor will not be clear until bills for the 2009 2nd installment are mailed out, likely in late November, 2010.