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; Buprenorphine used in Treatment; Naltrexone used in Treatment; No formal relationship with prescribing entity; Prescribes buprenorphine; Accepts clients using MAT but prescribed elsewhere; Buprenorphine with naloxone; Buprenorphine (extended-release, injectable); Naltrexone (oral); Naltrexone (extended-release, injectable); Medication for mental disorders; Nicotine replacement; Private for-profit organization; State Substance use treatment agency; State mental health department; State department of health; Commission on Accreditation of Rehabilitation Facilities (CARF); Medicare; Medicaid; Federal military insurance (e.g., TRICARE); Private health insurance; Cash or self-payment; State-financed health insurance plan other than Medicaid; Sliding fee scale (fee is based on income and other factors); Adolescents; Young adults; Comprehensive mental health assessment; Comprehensive substance use assessment; Interim services for clients; Outreach to persons in the community; Screening for substance use; Screening for mental disorders; Drug or alcohol urine screening; Aftercare/continuing care; Discharge Planning; Naloxone and overdose education; Outcome follow-up after discharge; Self-help groups; Housing services; Assistance with obtaining social services; Mentoring/peer support; Employment counseling or training; Methamphetamines detoxification; Opioids detoxification; Medication routinely used during detoxification; Substance use disorder education; Individual counseling; Group counseling; Family counseling; Marital/couples counseling; Smoking permitted in designated area; Children/adolescents; Female; Male; Specially designed program for DUI/DWI clients; Case management service; Domestic violence services, including family or partner; Mental health services; Social skills development; Transportation assistance