Substance use treatment; Detoxification; Treatment for co-occurring substance use plus either serious mental health illness in adults/serious emotional disturbance in children; Outpatient; Outpatient detoxification; Outpatient methadone/buprenorphine or naltrexone treatment; Regular outpatient treatment; Methadone used in Treatment; Buprenorphine used in Treatment; Does not treat alcohol use disorder; Buprenorphine maintenance; Federally-certified Opioid Treatment Program; Methadone maintenance; Prescribes buprenorphine; Methadone; Buprenorphine with naloxone; Buprenorphine without naloxone; Buprenorphine (extended-release, injectable); Medications for HIV treatment; Medications for Hepatitis C treatment; Medication for mental disorders; Substance use disorder counseling; Private for-profit organization; State Substance use treatment agency; Commission on Accreditation of Rehabilitation Facilities (CARF); Federal, or any government funding for substance use treatment programs; Medicare; Medicaid; Federal military insurance (e.g., TRICARE); 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); Pregnant/postpartum women; Clients with co-occurring mental and substance use disorders; Clients with HIV or AIDS; Clients who have experienced trauma; Comprehensive mental health assessment; Comprehensive substance use assessment; Outreach to persons in the community; Complete medical history/physical exam; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Breathalyzer or blood alcohol testing; Drug or alcohol urine screening; HIV testing; STD testing; 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; 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; Hepatitis A (HAV) vaccination; Hepatitis B (HBV) vaccination; Smoking not permitted; Female; Male; Opioid use disorder clients only; Vaping not permitted; Case management service; Early intervention for HIV; Mental health services; Social skills development; Integrated primary care services