This document addresses the significant health disparities in substance use disorder (SUD) among racially, ethnically, and historically marginalized populations, including AI/AN, Black, Hispanic/Latino, and LGBTQI+ communities. It explores strategies to reduce these disparities through research, policy evaluation, training, and innovative practices. Key goals include improving SUD health literacy, expanding treatment access, increasing representation in SUD services, and understanding how these efforts can enhance equity and outcomes for marginalized populations. This resource was provided by SAMHSA.