Substance use treatment; Detoxification; Outpatient; Outpatient detoxification; 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 detoxification; Methadone maintenance; Methadone maintenance for predetermined time; Methadone; Brief intervention; Relapse prevention; Substance use disorder counseling; Private for-profit organization; State department of health; Commission on Accreditation of Rehabilitation Facilities (CARF); SAMHSA certification for opioid treatment program (OTP); Drug Enforcement Agency (DEA); Federal military insurance (e.g., TRICARE); Cash or self-payment; Comprehensive substance use assessment; Interim services for clients; Outreach to persons in the community; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Drug or alcohol urine screening; STD testing; TB screening; Testing for Hepatitis C (HCV); Aftercare/continuing care; Discharge Planning; Outcome follow-up after discharge; Self-help groups; Housing services; Assistance with obtaining social services; Employment counseling or training; Opioids detoxification; Medication routinely used during detoxification; 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; Family counseling; Marital/couples counseling; Smoking not permitted; Adults; Young adults; Female; Male; Opioid use disorder clients only; Vaping not permitted; Case management service; Early intervention for HIV; Social skills development; Transportation assistance