|2020 Summary Statistics for Township Equalization|
| 3 Year
Equalization is the application of a uniform percentage increase or decrease to assessed values of various areas or classes of property in order to bring assessment levels, on average, to the same percentage of market value.
In Lake County, on an annual basis the Chief County Assessment Officer determines the level of assessment in each township based upon the sales transactions that have occurred in the three years prior to the assessment date. This year's assessment valuation data is January 1, 2020. In analyzing the sales from the three previous years (2017, 2018, 2019) the CCAO takes the median level of assessment for each of those years, averages those medians, to determine the adjustment in assessments required in a township. Once the assessor has completed their assessment roll for the year, the CCAO analyzes the changes in assessments by class (residential, commercial and industrial) and determines what further adjustments are needed in a township, by applying a township multiplier to all non-farm parcels in the jurisdiction.
The Equalization Process
The equalization process is intended to bring the three year average of the median assessment levels in a township to 33.33% of market value, which is our statutory requirement in Illinois. Once the Lake County Board of Review has finalized its work in a given tax year, the Illinois Department of Revenue then takes on its role in performing equalization that is applicable to the entire county.
Illinois Department of Revenue Publication 136 (PDF)
Sales Ratio Studies
PTAX-215 - Assessment Ratios Adjusted for Changes through 2018