Substance use treatment; Outpatient; Outpatient methadone/buprenorphine or naltrexone treatment; Methadone used in Treatment; Buprenorphine used in Treatment; Does not treat alcohol use disorder; Buprenorphine detoxification; Buprenorphine maintenance; Buprenorphine maintenance for predetermined time; Federally-certified Opioid Treatment Program; Methadone detoxification; Methadone maintenance; Methadone maintenance for predetermined time; Methadone; Buprenorphine with naloxone; Buprenorphine without naloxone; Brief intervention; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Telemedicine/telehealth therapy; 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); Medicare; Medicaid; Federal military insurance (e.g., TRICARE); Cash or self-payment; Young adults; Adult women; Pregnant/postpartum women; Adult men; Comprehensive substance use assessment; Outreach to persons in the community; Screening for tobacco use; Screening for substance use; Breathalyzer or blood alcohol testing; Drug and alcohol oral fluid testing; Drug or alcohol urine screening; TB screening; Testing for Hepatitis C (HCV); Aftercare/continuing care; Discharge Planning; Naloxone and overdose education; Outcome follow-up after discharge; Mentoring/peer support; Opioids detoxification; Medication routinely used during detoxification; Substance use disorder education; Smoking/vaping/tobacco cessation counseling; Individual counseling; Smoking not permitted; Adults; Young adults; Female; Male; Opioid use disorder clients only; Vaping not permitted; Case management service; Suicide prevention services