November 12, 2025
Click here to read the full report
Click here to read the press release
Click here to view the executive summary
Download the data for all Cook County taxing agencies subject to PTELL
Illinois’ Property Tax Extension Limitation Law (PTELL) was enacted in the 1990s to slow the rate of growth of local property taxes by capping the annual increases in property tax extensions for non-home rule governments, such as school districts and park districts, to the lesser of 5% or the rate of inflation. In reality, property taxes have grown much faster than inflation, and PTELL has not achieved its intended purpose of limiting property tax growth.
The primary reason is that the law itself contains exclusions and exceptions that allow growth well beyond the intended limit. The result is a system that presents an illusion of a “cap” to protect taxpayers while, in reality, governments are saddling property owners with ever-higher bills.
This report sheds light on the limitations of the law itself, explores why PTELL has not been working as intended, provides examples of the impact on taxpayers using Chicago Public Schools as a case study, and ends with a brief analysis of what property tax collections would look like if PTELL truly did limit growth. The Civic Federation and Mansueto Institute for Urban Innovation present these findings to establish a common set of data and facts from which policymakers, taxpayers, and local officials can, and should, discuss reform.