Substance use treatment; Treatment for co-occurring substance use plus either serious mental health illness in adults/serious emotional disturbance in children; Outpatient; Outpatient methadone/buprenorphine or naltrexone treatment; Regular outpatient treatment; Buprenorphine used in Treatment; Does not treat alcohol use disorder; Buprenorphine detoxification; Buprenorphine maintenance; Buprenorphine maintenance for predetermined time; Prescribes buprenorphine; Buprenorphine with naloxone; Buprenorphine without naloxone; Buprenorphine (extended-release, injectable); Medications for Hepatitis C treatment; Medication for mental disorders; Substance use disorder counseling; Private for-profit organization; State department of health; Cash or self-payment; Comprehensive mental health assessment; Comprehensive substance use assessment; Outreach to persons in the community; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Drug and alcohol oral fluid testing; HIV testing; STD testing; Testing for Hepatitis B (HBV); Testing for Hepatitis C (HCV); Naloxone and overdose education; Benzodiazepines Detoxification; Cocaine Detoxification; Methamphetamines detoxification; Opioids detoxification; Medication routinely used during detoxification; Substance use disorder education; Smoking/vaping/tobacco cessation counseling; Individual counseling; Smoking permitted without restriction; Adults; Young adults; Female; Male; Opioid use disorder clients only; Vaping permitted without restriction; Mental health services