Negative attitudes and stigmatization of substance-using patients lead to treatment avoidance and poor physical and health outcomes. Research suggests that training in substance use disorders is a vital tool to abate negative attitudes among health workers. The present longitudinal study trained students and experienced practitioners from various disciplines on the evidence-based Screening, Brief Intervention, and Referral to Treatment (SBIRT) model. The study found significant improvements in the attitudes of students—but not practitioners—who were trained during the program. The paper discusses policy and implementation implications to support and complement sustained impact of training on models such as SBIRT.