This research analyzed the effect that the General State Aid (GSA) Property Tax Extension Limitation Law adjustment and Hold Harmless component had on equity in the Illinois General State Aid funding system. The equity criteria defined in the study were permissible variance, wealth neutrality, and conditional wealth neutrality. This study consisted of four simulations. First, baseline indices were calculated for the Illinois GSA funding system for 2000 to 2011. Second, the Property Tax Extension Limitation Law adjustment (PTELL) was eliminated, the associated cost savings used to increase the GSA foundation level, and new equity indices were calculated. Third, the Hold Harmless component was eliminated, the associated cost savings were used to increase the foundation level, and new equity indices were calculated. Finally, the PTELL adjustment and Hold Harmless component were both eliminated, the combined cost savings were used to increase the GSA foundation level, and new equity indices were calculated. The simulated indices were compared to the baseline values to determine the effect on equity.The permissible variance criterion was measured using the Mcloone Index and coefficient of variation. A simple regression coefficient was used to measure the wealth neutrality criterion. Finally, the conditional wealth neutrality criterion was measured using the change in R 2 from a 2-step multiple regression (controlling for local tax rate).Some major findings of the study included:1. Unit school districts were more equitable than elementary and high school districts across all equity measures and simulations.2. High school districts were the least equitable of all school district types.3. The simulations that included the elimination of the PTELL adjustment improved the equity in the Illinois funding system across all measures and school district types.