Voting District Project of the Census Redistricting Data Program commenced in Summer of 2017 to establish the state’s Voting precincts within the bureau’s tiger geography. The initial phase used the Bureau’s GUPS plugin for QGIS to update the districts from the 2010 round, and then a secondary verification phase took place to ensure the updated voting districts were properly enacted into Tiger geographic files. A post census effort took place in December 2021 to cut the number of precincts down countywide to 1430.
Election Data Services conducted Phase 2 of the Census Redistricting Data Program for the State of Illinois, as well as implemented changes made post census in Cook County.
Precincts are updated as needed before every election by the Cook County Clerk's Elections Department.