Substance use treatment; Treatment for co-occurring substance use plus either serious mental health illness in adults/serious emotional disturbance in children; Outpatient; Intensive outpatient treatment; Outpatient methadone/buprenorphine or naltrexone treatment; Regular outpatient treatment; Buprenorphine used in Treatment; Naltrexone used in Treatment; No formal relationship with prescribing entity; Accepts clients using medication assisted treatment for alcohol use disorder but prescribed elsewhere; No formal relationship with prescribing entity; Buprenorphine detoxification; Buprenorphine maintenance; Buprenorphine maintenance for predetermined time; Prescribes buprenorphine; Prescribes naltrexone; Accepts clients using MAT but prescribed elsewhere; Buprenorphine with naloxone; Buprenorphine without naloxone; Naltrexone (oral); Medication for mental disorders; Nicotine replacement; Anger management; Brief intervention; Cognitive behavioral therapy; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Trauma-related counseling; Telemedicine/telehealth therapy; Private non-profit organization; State Substance use treatment agency; State mental health department; Commission on Accreditation of Rehabilitation Facilities (CARF); Medicare; Medicaid; Private health insurance; Cash or self-payment; SAMHSA funding/block grants; Clients with co-occurring mental and substance use disorders; Comprehensive mental health assessment; Comprehensive substance use assessment; Outreach to persons in the community; Screening for substance use; Screening for mental disorders; Drug or alcohol urine screening; Discharge Planning; Naloxone and overdose education; Outcome follow-up after discharge; Housing services; Assistance with obtaining social services; Recovery coach; Substance use disorder education; Individual counseling; Group counseling; Family counseling; Marital/couples counseling; Smoking not permitted; Female; Male; Sign language services for the deaf and hard of hearing; Vaping not permitted; Case management service; Mental health services