The Facility-wide Tiered Fidelity Inventory (FW-TFI) is a treatment fidelity tool used to evaluate implementation of positive behavior interventions and support (PBIS) framework systems, data, and practices at Tiers I, II, and III in residential and juvenile facilities where the needs of the children and youth are served within 24-hour/7-day a week service delivery models. This manuscript details the development process undertaken to adapt the School-wide Tiered Fidelity Inventory for use when PBIS is implemented across all settings by all staff of a facility. A three-stage process, involving a representative sample of national stakeholders, is detailed, with each phase briefly described along with ideas shared and decisions made by the stakeholders. We offer two illustrative examples of the FW-TFI process undertaken and the data gleaned from implementation with a hypothetical therapeutic residential hospital and residential juvenile facility. We conclude with practice and policy implications.