Primary care residency programs continue to adapt and change to become high-performing training sites for advanced primary care. Practice facilitation is a key method to assist practices in implementing organizational changes. This evaluation described the unique nature and essential roles and qualities of practice facilitation for residency program patient-centered medical home (PCMH) transformation.Evaluation of the Colorado Residency PCMH Project from 2009 through 2014 included template and immersion-crystallization approaches to qualitative analysis of field notes, key informant interviews, and meeting documentation to identify themes related to external facilitation for practice transformation in 11 Colorado primary care residency practices.Important practice facilitator roles in residency practice transformation included supporter of quality improvement and NCQA implementation, connector of practices, and leadership and engagement coach. Key qualities included the relationship development between practice members and facilitators over time, flexibility, consistent presence and communication, and an external nature that provided a valuable outside perspective.Residency programs provide a unique environment that is particularly well-suited for transformation, though it also presents challenges. External practice facilitators that demonstrate key roles and qualities can support residency practices through this complex transformation process.