Substance use treatment; Outpatient; Intensive outpatient treatment; Outpatient methadone/buprenorphine or naltrexone treatment; Methadone used in Treatment; Does not treat alcohol use disorder; Federally-certified Opioid Treatment Program; Methadone maintenance for predetermined time; Methadone; Substance use disorder counseling; Private for-profit organization; State Substance use treatment agency; State department of health; Commission on Accreditation of Rehabilitation Facilities (CARF); Federally Qualified Health Center; Medicare; Medicaid; Private health insurance; Cash or self-payment; Adult women; Pregnant/postpartum women; Adult men; Seniors or older adults; Comprehensive substance use assessment; Complete medical history/physical exam; Screening for tobacco use; Screening for substance use; Professional interventionist/educational consultant; Breathalyzer or blood alcohol testing; Drug and alcohol oral fluid testing; Drug or alcohol urine screening; TB screening; Metabolic syndrome monitoring; Aftercare/continuing care; Discharge Planning; Naloxone and overdose education; Housing services; Assistance with obtaining social services; Employment counseling or training; Opioids detoxification; Medication routinely used during detoxification; Substance use disorder education; Individual counseling; Group counseling; Smoking permitted in designated area; Adults; Seniors; Young adults; Female; Male; Opioid use disorder clients only; Vaping permitted in designated area; Case management service; Integrated primary care services; Suicide prevention services