Substance use treatment; Outpatient; Outpatient methadone/buprenorphine or naltrexone treatment; Regular outpatient treatment; Methadone used in Treatment; Naltrexone used in Treatment; Does not treat alcohol use disorder; Federally-certified Opioid Treatment Program; Methadone maintenance; Methadone; Medication for mental disorders; Nicotine replacement; Anger management; Brief intervention; Cognitive behavioral therapy; Contingency management/motivational incentives; Motivational interviewing; Matrix Model; Relapse prevention; Substance use disorder counseling; Telemedicine/telehealth therapy; Trauma-related counseling; Private for-profit organization; State Substance use treatment agency; Commission on Accreditation of Rehabilitation Facilities (CARF); 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); Adult women; Pregnant/postpartum women; Adult men; Clients with co-occurring mental and substance use disorders; Comprehensive mental health assessment; Comprehensive substance use assessment; Complete medical history/physical exam; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Breathalyzer or blood alcohol testing; Drug and alcohol oral fluid testing; Drug or alcohol urine screening; 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; Housing services; Assistance with obtaining social services; Mentoring/peer support; Substance use disorder education; Individual counseling; Group counseling; Family counseling; Smoking not permitted; Adults; Young adults; Female; Male; Opioid use disorder clients only; Sign language services for the deaf and hard of hearing; Vaping permitted without restriction; Mental health services