Substance use treatment; Outpatient; Outpatient methadone/buprenorphine or naltrexone treatment; Regular outpatient treatment; Methadone used in Treatment; Does not treat alcohol use disorder; Federally-certified Opioid Treatment Program; Methadone maintenance; Methadone; Substance use disorder counseling; Private for-profit organization; State Substance use treatment agency; Federally Qualified Health Center; SAMHSA certification for opioid treatment program (OTP); Drug Enforcement Agency (DEA); Medicaid; Private health insurance; Cash or self-payment; Comprehensive substance use assessment; Screening for tobacco use; Screening for substance use; Drug or alcohol urine screening; HIV testing; TB screening; Metabolic syndrome monitoring; Testing for Hepatitis C (HCV); Aftercare/continuing care; Discharge Planning; Naloxone and overdose education; Outcome follow-up after discharge; Assistance with obtaining social services; 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 permitted without restriction; Children/adolescents; Female; Male; Opioid use disorder clients only; Vaping permitted without restriction