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 use medication assisted treatment for alcohol use disorder; Does not treat opioid use disorders; Private non-profit organization; State Substance use treatment agency; State mental health department; Federal, or any government funding for substance use treatment programs; Medicaid; Federal military insurance (e.g., TRICARE); Private health insurance; Cash or self-payment; Sliding fee scale (fee is based on income and other factors); Adolescents; Criminal justice (other than DUI/DWI)/Forensic clients; Clients with co-occurring mental and substance use disorders; Clients who have experienced trauma; Comprehensive substance use assessment; Outreach to persons in the community; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Discharge Planning; Outcome follow-up after discharge; Assistance with obtaining social services; Substance use disorder education; Individual counseling; Group counseling; Family counseling; Smoking not permitted; Adults; Children/adolescents; Young adults; Female; Male; Vaping not permitted; Case management service; Mental health services; Social skills development