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; Does not treat alcohol use disorder; Does not treat opioid use disorders; Medication for mental disorders; Anger management; Cognitive behavioral therapy; Motivational interviewing; Trauma-related counseling; Telemedicine/telehealth therapy; Private for-profit organization; State mental health department; State department of health; Medicare; Medicaid; Federal military insurance (e.g., TRICARE); Private health insurance; Cash or self-payment; Adolescents; Young adults; Adult women; Pregnant/postpartum women; Adult men; Seniors or older adults; Lesbian, gay, bisexual, transgender, or queer/questioning (LGBTQ); Veterans; Active duty military; Members of military families; Criminal justice (other than DUI/DWI)/Forensic clients; Clients with co-occurring mental and substance use disorders; Clients with co-occurring pain and substance use disorders; Clients who have experienced sexual abuse; Clients who have experienced trauma; Comprehensive mental health assessment; Complete medical history/physical exam; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Discharge Planning; Outcome follow-up after discharge; Treatment for other addiction disorder; Individual counseling; Group counseling; Family counseling; Marital/couples counseling; Smoking permitted in designated area; Seniors; Female; Male; Spanish; Vaping permitted in designated area; Mental health services