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; Other contracted prescribing entity; Accepts clients using medication assisted treatment for alcohol use disorder but prescribed elsewhere; Other contracted prescribing entity; Accepts clients using MAT but prescribed elsewhere; Cognitive behavioral therapy; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Telemedicine/telehealth therapy; Trauma-related counseling; Private non-profit organization; State Substance use treatment agency; State mental health department; State department of health; Federal, or any government funding for substance use treatment programs; Medicaid; Private health insurance; Cash or self-payment; Adolescents; Young adults; Adult women; Pregnant/postpartum women; Adult men; Clients with co-occurring mental and substance use disorders; Comprehensive mental health assessment; Comprehensive substance use assessment; Interim services for clients; Screening for substance use; Screening for mental disorders; Drug or alcohol urine screening; Smoking permitted without restriction; Children/adolescents; Female; Male; Specially designed program for DUI/DWI clients; Spanish; Vaping not permitted