In the last decade the US federal government proposed a transformation vision of mental health service delivery; patient-centered, evidence-based and recovery oriented treatment models. Health care reform brings additional expectations for innovation in mental/substance use service delivery, particularly the idea of creating systems where physical health, mental health and substance use treatment is fully integrated. Psychiatric nurses, as one of the four core US mental health professions, have the potential to play a significant role in the both the transformation initiative and health care reform vision. However, psychiatric nurses, particularly advanced practice psychiatric nurses, are an untapped resource due in part to significant state regulatory barriers that limit their scope of practice in many states. The purpose of this paper is to document what is currently known about advanced practice psychiatric nurses and discuss policy implications for tapping into the strengths of this workforce. Strategies for facilitating utilization of advanced practice psychiatric nurses discussed.