Substance use treatment; Treatment for co-occurring substance use plus either serious mental health illness in adults/serious emotional disturbance in children; Outpatient; Regular outpatient treatment; No formal relationship with prescribing entity; Accepts clients using medication assisted treatment for alcohol use disorder but prescribed elsewhere; No formal relationship with prescribing entity; Accepts clients using MAT but prescribed elsewhere; Cognitive behavioral therapy; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Trauma-related counseling; Telemedicine/telehealth therapy; Private non-profit organization; State Substance use treatment agency; State mental health department; Council on Accreditation (COA); Federal, or any government funding for substance use treatment programs; Medicaid; Private health insurance; Cash or self-payment; State-financed health insurance plan other than Medicaid; SAMHSA funding/block grants; Adolescents; Clients with co-occurring mental and substance use disorders; Clients who have experienced sexual abuse; Clients who have experienced trauma; Comprehensive mental health assessment; Comprehensive substance use assessment; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Aftercare/continuing care; Discharge Planning; Outcome follow-up after discharge; Substance use disorder education; Smoking/vaping/tobacco cessation counseling; Individual counseling; Group counseling; Family counseling; Smoking not permitted; Children/adolescents; Female; Male; Vaping not permitted; Case management service; Mental health services; Social skills development; Suicide prevention services