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; Does not use medication assisted treatment for alcohol use disorder; Prescribes buprenorphine; Prescribes naltrexone; Acamprosate (Campral®); Disulfiram; Buprenorphine with naloxone; Naltrexone (oral); Naltrexone (extended-release, injectable); Clonidine; Medication for mental disorders; Non-nicotine smoking/tobacco cessation; Cognitive behavioral therapy; Relapse prevention; Substance use disorder counseling; Telemedicine/telehealth therapy; Private for-profit organization; State Substance use treatment agency; The Joint Commission; Federal military insurance (e.g., TRICARE); Private health insurance; Cash or self-payment; Adult women; Adult men; Clients with co-occurring mental and substance use disorders; Clients who have experienced sexual abuse; Clients who have experienced trauma; Comprehensive mental health assessment; Comprehensive substance use assessment; Outreach to persons in the community; Screening for substance use; Screening for mental disorders; Breathalyzer or blood alcohol testing; Drug and alcohol oral fluid testing; Drug or alcohol urine screening; TB screening; Aftercare/continuing care; Discharge Planning; Outcome follow-up after discharge; Self-help groups; Housing services; Assistance with obtaining social services; Recovery coach; Mentoring/peer support; Health education services other than HIV/AIDS or hepatitis; Substance use disorder education; Individual counseling; Group counseling; Family counseling; Marital/couples counseling; Smoking permitted in designated area; Adults; Young adults; Female; Male; Specially designed program for DUI/DWI clients; Case management service; Mental health services; Social skills development; Transportation assistance