Substance Use Disorder (SUD) is a chronic relapsing disease that afflicts 10% of the US population. Recidivism rates for SUD treatment in the United States (US) remain high. Couple therapy has be shown to be an effective treatment modality for SUD, and research consistently indicates that couple therapy is more effective than individual therapy in treating SUD. Still, most US treatment centers do not use couple therapy as a primary treatment modality. To explore the underuse of couple therapy and the barriers that prevent its use, individual, semi-structured interviews were conducted with twenty (N = 20) clinical directors of SUD treatment centers across the US. A theoretical thematic analysis was used incorporating Everett Rogers’ diffusion of innovations theory to assess barriers that hinder the use of couple therapy to treat SUD in addiction treatment centers. Issues related to observability, compatibility, and complexity of couple treatment were found to severely impede the implementation of couple therapy in addiction treatment centers. Recommendations include ongoing research to determine influences on agency programming, fostering pro-research environments in universities and agencies, removing barriers to access to evidence-based practice information, and promoting the federal initiative of technology transfer in SUD treatment. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection