Programs that provide coordinated treatment services for individuals who have a diagnosed mental illness which interferes with their functioning in a substantial way in combination with a substance use disorder that aggravates their ability to become stabilized or recover. Both psychiatric and substance use disorder treatment are provided at the same time, at the same place and by the same multidisciplinary team or a single provider trained and competent in co-occurring disorders. The approach seeks to treat the whole person instead of looking only at one issue at a time; mental illnesses and substance use disorders are seen as intertwined, not separate.