Substance use treatment; Detoxification; Outpatient; Outpatient methadone/buprenorphine or naltrexone treatment; Regular outpatient treatment; Methadone used in Treatment; Does not treat alcohol use disorder; Federally-certified Opioid Treatment Program; Methadone detoxification; Methadone maintenance; Methadone maintenance for predetermined time; Methadone; Cognitive behavioral therapy; Contingency management/motivational incentives; Relapse prevention; Substance use disorder counseling; 12-step facilitation; Private for-profit organization; State Substance use treatment agency; State department of health; The Joint Commission; SAMHSA certification for opioid treatment program (OTP); Drug Enforcement Agency (DEA); Cash or self-payment; Adult women; Pregnant/postpartum women; Adult men; Clients with co-occurring pain and substance use disorders; Comprehensive substance use assessment; Outreach to persons in the community; Complete medical history/physical exam; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Professional interventionist/educational consultant; Drug or alcohol urine screening; HIV testing; STD testing; TB screening; Testing for Hepatitis B (HBV); Testing for Hepatitis C (HCV); Aftercare/continuing care; Discharge Planning; Outcome follow-up after discharge; Housing services; Employment counseling or training; Opioids detoxification; Medication routinely used during detoxification; Hepatitis education, counseling, or support; Substance use disorder education; Individual counseling; Group counseling; Family counseling; Marital/couples counseling; Smoking permitted without restriction; Children/adolescents; Female; Male; Specially designed program for DUI/DWI clients; Opioid use disorder clients only; Vaping permitted without restriction; Case management service; Domestic violence services, including family or partner; Mental health services; Integrated primary care services; Suicide prevention services