Substance use treatment; Outpatient; Outpatient day treatment or partial hospitalization; 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; Brief intervention; Cognitive behavioral therapy; Contingency management/motivational incentives; Community reinforcement plus vouchers; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Telemedicine/telehealth therapy; Private non-profit organization; Commission on Accreditation of Rehabilitation Facilities (CARF); Medicare; Medicaid; Cash or self-payment; Sliding fee scale (fee is based on income and other factors); Adult women; Adult men; Seniors or older adults; Comprehensive substance use assessment; Outreach to persons in the community; Screening for substance use; Screening for mental disorders; 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; Employment counseling or training; HIV or AIDS education, counseling, or support; Hepatitis education, counseling, or support; Substance use disorder education; Individual counseling; Group counseling; Family counseling; Hepatitis A (HAV) vaccination; Hepatitis B (HBV) vaccination; Smoking permitted in designated area; Seniors; Female; Male; Opioid use disorder clients only; Other languages (excluding Spanish); Any Chinese Language; Korean; Russian; Vaping permitted in designated area; Case management service