Community engagement research is widely discussed but rarely implemented. This article describes the implementation of a community engagement research project on Dual Diagnosis Anonymous, a rapidly spreading peer support program in Oregon for people with co-occurring mental illness and substance use disorders. After three years of discussions, overcoming barriers, and involving several institutions, this grassroots research project has been implemented and is expanding. Active participants in Dual Diagnosis Anonymous inspired and instructed policy makers, professionals, and students. Community engagement research requires frontline participants, community members, and professional collaborators to overcome multiple barriers with persistence and steadfastness. Building trust, collaboration, and structures for community engagement research takes time and a community effort.