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 detoxification; Buprenorphine maintenance; Buprenorphine maintenance for predetermined time; Federally-certified Opioid Treatment Program; Methadone detoxification; Methadone maintenance; Methadone maintenance for predetermined time; Prescribes buprenorphine; Methadone; Buprenorphine with naloxone; Brief intervention; Cognitive behavioral therapy; Contingency management/motivational incentives; Matrix Model; Relapse prevention; Substance use disorder counseling; Telemedicine/telehealth therapy; Private for-profit organization; State Substance use treatment agency; Commission on Accreditation of Rehabilitation Facilities (CARF); SAMHSA certification for opioid treatment program (OTP); Drug Enforcement Agency (DEA); 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; Young adults; Adult women; Pregnant/postpartum women; Adult men; Comprehensive substance use assessment; Outreach to persons in the community; Screening for substance use; 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); Discharge Planning; Naloxone and overdose education; Outcome follow-up after discharge; Self-help groups; Housing services; Assistance with obtaining social services; Mentoring/peer support; Opioids detoxification; Medication routinely used during detoxification; HIV or AIDS education, counseling, or support; Hepatitis education, counseling, or support; Substance use disorder education; Individual counseling; Group counseling; Marital/couples counseling; Smoking not permitted; Adults; Young adults; Female; Male; Opioid use disorder clients only; Vaping not permitted; Case management service; Social skills development; Transportation assistance