Substance use treatment; Treatment for co-occurring substance use plus either serious mental health illness in adults/serious emotional disturbance in children; Outpatient; Regular outpatient treatment; Does not use medication assisted treatment for alcohol use disorder; Does not treat opioid use disorders; Private non-profit organization; State Substance use treatment agency; State mental health department; State department of health; Council on Accreditation (COA); Federally Qualified Health Center; 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; SAMHSA funding/block grants; Comprehensive mental health assessment; Screening for substance use; Screening for mental disorders; Professional interventionist/educational consultant; Mentoring/peer support; Individual counseling; Group counseling; Family counseling; Smoking permitted in designated area; Female; Male; Vaping not permitted; Mental health services; Suicide prevention services