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; Other contracted prescribing entity; Does not use medication assisted treatment for alcohol use disorder; Buprenorphine maintenance; Prescribes buprenorphine; Prescribes naltrexone; Relapse prevention with naltrexone; Accepts clients using MAT but prescribed elsewhere; Buprenorphine with naloxone; Buprenorphine without naloxone; Naltrexone (extended-release, injectable); Cognitive behavioral therapy; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Telemedicine/telehealth therapy; 12-step facilitation; Private non-profit organization; State Substance use treatment agency; State mental health department; Federal, or any government funding for substance use treatment programs; SAMHSA funding/block grants; Payment assistance (check with facility for details); Clients with co-occurring mental and substance use disorders; Comprehensive substance use assessment; Outreach to persons in the community; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Breathalyzer or blood alcohol testing; Drug or alcohol urine screening; TB screening; Aftercare/continuing care; Discharge Planning; Self-help groups; Housing services; Mentoring/peer support; Substance use disorder education; Individual counseling; Group counseling; Smoking permitted in designated area; Adults; Young adults; Female; Male; Vaping permitted in designated area; Case management service; Mental health services; Transportation assistance