The Program Fidelity Scale (PFS) is the central reference document for DBT program reviews. Initially developed with Marsha Linehan and a small group of her clinical colleagues, it sought to identify those core elements of a DBT program that distinguished it from other types of treatment and other programs. All assessments for program review refer back to the PFS, with the goal of determining whether a program is meeting a minimum standard of implementation (or a reasonable alternative). After ten years of reviewing programs, a workgroup including some of the original developers plus experienced reviewers used their experience to create the next generation of PFS, which utilizes published manuals, research and descriptive articles by Linehan and her colleagues to catalog the elements that make DBT unique, and effective. As with the first iteration, the new PFS provides the backbone of program review. It is offered free of charge to the DBT community, to inform clinicians and clients of the components of a comprehensive DBT program. It is suggested that DBT teams use the PFS as a self-study checklist, to ensure that their program is operating consistently with those programs that have demonstrated effective treatment in published research. And it is a key aspect of the application process, where teams and team leads review their adherence to each element as a pre-requisite to seeking DBT-LBC program certification.