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; Does not use medication assisted treatment for alcohol use disorder; Federally-certified Opioid Treatment Program; Methadone detoxification; Methadone maintenance; Methadone maintenance for predetermined time; Methadone; Anger management; Brief intervention; Cognitive behavioral therapy; Motivational interviewing; Matrix Model; Relapse prevention; Substance use disorder counseling; Trauma-related counseling; Telemedicine/telehealth therapy; Private for-profit organization; State Substance use treatment agency; State mental health department; Commission on Accreditation of Rehabilitation Facilities (CARF); Drug Enforcement Agency (DEA); Medicaid; Cash or self-payment; State-financed health insurance plan other than Medicaid; Adult women; Pregnant/postpartum women; Adult men; Seniors or older adults; Clients with co-occurring mental and substance use disorders; Clients who have experienced intimate partner violence, domestic violence; Clients who have experienced trauma; Comprehensive substance use assessment; Interim services for clients; 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 and alcohol oral fluid testing; Drug or alcohol urine screening; HIV testing; STD testing; TB screening; 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; Individual counseling; Group counseling; Family counseling; Marital/couples counseling; Smoking not permitted; Adults; Seniors; Young adults; Female; Male; Vaping not permitted; Case management service; Mental health services; Social skills development; Suicide prevention services