An estimated 15.2 percent of Illinois’ workers are represented by a union. These workers can voluntarily choose to leave their unionized workplace, opt out of paying certain dues, or vote to decertify their labor organization. Thus, labor unions in Illinois must continually demonstrate how workers benefit from contributing membership dues. This Policy Brief, conducted jointly by the he Project for Middle-Class Renewal (PMCR) at the School of Labor and Employment Relations, University of Illinois at Urbana-Champaign, and the Illinois Economic Policy Institute (ILEPI) evaluates union membership in Illinois. The report breaks down how union dues are spent in Illinois by activity, including political activities and lobbying. Upon examining the individual cost of membership and where dollars go, the personal benefits of union membership for Illinois workers are also explored.