Check-In, Check-Out (CICO) is one of the most widely implemented Tier 2 behavior interventions in a school-wide system of Positive Behavior Interventions and Supports (PBIS). Much literature has documented implementation of CICO across individual schools or districts. The Illinois PBIS Network, currently known as the Midwest PBIS Network, has provided extensive training and technical assistance (TA) on CICO with more than 400 schools in more than 125 districts. The purpose of this descriptive study was to detail the training process for implementation of CICO across 441 schools, evaluate student success based on Daily Progress Reports (DPRs), and document fidelity and implementation on a subset of 41 elementary and 13 middle schools. Results indicated more than 80% of students earned at least 80% of their DPR points, the majority of schools implemented CICO with more than 70% fidelity, and schools were able to support between 7% and 12% of student population on CICO. Implications for practice and suggestions for future research are included.