Substance use treatment; Outpatient; Outpatient methadone/buprenorphine or naltrexone treatment; Methadone used in Treatment; Buprenorphine used in Treatment; Naltrexone used in Treatment; Does not treat alcohol use disorder; Buprenorphine maintenance; Buprenorphine maintenance for predetermined time; Federally-certified Opioid Treatment Program; Methadone maintenance; Methadone maintenance for predetermined time; Prescribes buprenorphine; Prescribes naltrexone; Relapse prevention with naltrexone; Methadone; Buprenorphine with naloxone; Buprenorphine without naloxone; Naltrexone (oral); Naltrexone (extended-release, injectable); Brief intervention; Cognitive behavioral therapy; Contingency management/motivational incentives; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Telemedicine/telehealth therapy; Trauma-related counseling; Private for-profit organization; State Substance use treatment agency; State department of health; Commission on Accreditation of Rehabilitation Facilities (CARF); SAMHSA certification for opioid treatment program (OTP); Drug Enforcement Agency (DEA); 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; State-financed health insurance plan other than Medicaid; SAMHSA funding/block grants; 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; 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; 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; Smoking/vaping/tobacco cessation counseling; Individual counseling; Group counseling; Smoking not permitted; Adults; Young adults; Female; Male; Opioid use disorder clients only; Spanish; Sign language services for the deaf and hard of hearing; Vaping not permitted; Case management service; Social skills development