Substance use treatment; Detoxification; Outpatient; Outpatient detoxification; Outpatient methadone/buprenorphine or naltrexone treatment; Regular outpatient treatment; Methadone used in Treatment; Buprenorphine used in Treatment; Naltrexone used in Treatment; Does not treat alcohol use disorder; Buprenorphine detoxification; Buprenorphine maintenance; Federally-certified Opioid Treatment Program; Methadone detoxification; Methadone maintenance; Prescribes buprenorphine; Prescribes naltrexone; Relapse prevention with naltrexone; Methadone; Buprenorphine with naloxone; Buprenorphine without naloxone; Naltrexone (oral); Anger management; Brief intervention; Contingency management/motivational incentives; Motivational interviewing; Matrix Model; Relapse prevention; Substance use disorder counseling; Telemedicine/telehealth therapy; 12-step facilitation; Private for-profit organization; State Substance use treatment agency; State department of health; Commission on Accreditation of Rehabilitation Facilities (CARF); Medicare; Medicaid; 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); Young adults; Adult women; Pregnant/postpartum women; Adult men; Seniors or older adults; Clients with co-occurring mental and substance use disorders; Comprehensive substance use assessment; Outreach to persons in the community; Complete medical history/physical exam; Screening for substance use; Breathalyzer or blood alcohol testing; Drug and alcohol oral fluid testing; 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; 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; Treatment for other addiction disorder; Opioids detoxification; Medication routinely used during detoxification; HIV or AIDS education, counseling, or support; Hepatitis education, counseling, or support; Health education services other than HIV/AIDS or hepatitis; Substance use disorder education; Individual counseling; Group counseling; Smoking not permitted; Adults; Seniors; Young adults; Female; Male; Opioid use disorder clients only; Spanish; Other languages (excluding Spanish); Italian; Vaping not permitted; Case management service; Mental health services; Social skills development