We conducted in-depth case studies of 10 health care professionals who actively provide primary medical care to adults with autism spectrum disorders. The study sought to understand their experiences in providing this care, the training they had received, the training they lack and their suggestions for encouraging more physicians to provide this care. Qualitative data were gathered by phone using a structured interview guide and analyzed using the framework approach. Challenges to providing care were identified at the systems, practice and provider, and education and training levels. Solutions and interventions targeting needed changes at each level were also proposed. The findings have implications for health care reform, medical school and residency training programs, and the development of best practices.