This paper provides a brief overview of the status of screening, assessment, and management of psychiatric problems in substance use disorder (SUD) treatment settings in the USA. The literature shows that current best clinical practices guidelines support integrated treatment of co-occurring disorders (CODs) in SUD treatment programs, but in practice such care occurs at a low–moderate frequency, and is implemented inconsistently and with uneven quality across treatment settings. Several barriers to the consistent implementation of empirically supported COD assessment and treatment are discussed, with the conclusion that progress with such implementation depends heavily on administrative and health care system support and investment.