Data on minimum state requirements for drug and alcohol counselors and mental health counselors in all 50 states and Washington, DC, suggest that training as a mental health counselor is primarily structured through formal education, whereas training as a substance abuse counselor resembles an apprentice model. Fewer states offer or require certification or licensure of substance abuse counselors, compared to mental health counselors. States that do offer such credentials for substance abuse counselors generally require more hours of supervised work experience and continuing education, but fewer hours of formal course work and practicum courses, and a lower level of formal education. Although these different models for training are valid, they each have different implications for clinical practice, dissemination of research findings to practice, and management within the service delivery model.