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; No formal relationship with prescribing entity; Does not use medication assisted treatment for alcohol use disorder; Accepts clients using MAT but prescribed elsewhere; Medication for mental disorders; Cognitive behavioral therapy; Relapse prevention; Substance use disorder counseling; Trauma-related counseling; Private non-profit organization; State Substance use treatment agency; State mental health department; SAMHSA certification for opioid treatment program (OTP); Federal, or any government funding for substance use treatment programs; Medicare; Medicaid; Federal military insurance (e.g., TRICARE); Private health insurance; Cash or self-payment; SAMHSA funding/block grants; Sliding fee scale (fee is based on income and other factors); Adolescents; Young adults; Adult women; Adult men; Seniors or older adults; Veterans; Active duty military; 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; Interim services for clients; Outreach to persons in the community; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Aftercare/continuing care; Discharge Planning; Naloxone and overdose education; Outcome follow-up after discharge; Alcohol Detoxification; Benzodiazepines Detoxification; Cocaine Detoxification; Methamphetamines detoxification; Opioids detoxification; Substance use disorder education; Individual counseling; Group counseling; Smoking permitted in designated area; Children/adolescents; Seniors; Female; Male; Sign language services for the deaf and hard of hearing; Vaping permitted in designated area; Case management service; Domestic violence services, including family or partner; Mental health services; Social skills development; Suicide prevention services