Primary Care Payment Reform (PCPR) is an alternative payment pilot program of MassHealth, with learning collaborative support from UMass Medical School, that introduces the principles of accountable care, behavioral health integration and patient-centered medical homes in primary care practices. The pilot demonstrated that behavioral health integration is a necessary component of whole-person care and a complex, but highly accomplishable task; numerous transformation strategies can support the clinical, financial and cultural challenges to integration; and alternative payment models are essential to support sustainable, expandable and successful behavioral health services in primary care.