Substance use treatment; Treatment for co-occurring substance use plus either serious mental health illness in adults/serious emotional disturbance in children; Outpatient; Intensive outpatient treatment; Regular outpatient treatment; In-network prescribing entity; No formal relationship with prescribing entity; Accepts clients using medication assisted treatment for alcohol use disorder but prescribed elsewhere; In-network prescribing entity; No formal relationship with prescribing entity; Accepts clients using MAT but prescribed elsewhere; Medication for mental disorders; Cognitive behavioral therapy; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Trauma-related counseling; Telemedicine/telehealth therapy; 12-step facilitation; Private for-profit organization; State Substance use treatment agency; The Joint Commission; Medicare; Medicaid; Federal military insurance (e.g., TRICARE); Private health insurance; Cash or self-payment; Veterans; Active duty military; Members of military families; Clients with co-occurring mental and substance use disorders; Clients who have experienced trauma; Interim services for clients; Aftercare/continuing care; Naloxone and overdose education; Outcome follow-up after discharge; Treatment for other addiction disorder; Health education services other than HIV/AIDS or hepatitis; Substance use disorder education; Individual counseling; Group counseling; Smoking permitted without restriction; Adults; Young adults; Female; Male; Vaping permitted without restriction; Case management service; Mental health services; Social skills development