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; Regular outpatient 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; Prescribes naltrexone; Accepts clients using MAT but prescribed elsewhere; Acamprosate (Campral®); Disulfiram; Naltrexone (oral); Naltrexone (extended-release, injectable); Medication for mental disorders; Nicotine replacement; Non-nicotine smoking/tobacco cessation; Private non-profit organization; State Substance use treatment agency; 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; Clients with co-occurring mental and substance use disorders; Comprehensive mental health assessment; Comprehensive substance use assessment; Interim services for clients; Outreach to persons in the community; Complete medical history/physical exam; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Drug and alcohol oral fluid testing; Drug or alcohol urine screening; Aftercare/continuing care; Discharge Planning; Treatment for gambling disorder; Treatment for other addiction disorder; Substance use disorder education; Individual counseling; Family counseling; Marital/couples counseling; Smoking permitted in designated area; Female; Male; Sign language services for the deaf and hard of hearing; Vaping permitted in designated area; Case management service; Mental health services; Integrated primary care services; Suicide prevention services