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 treat alcohol use disorder; Does not treat opioid use disorders; Medication for mental disorders; Anger management; Brief intervention; Contingency management/motivational incentives; Trauma-related counseling; Telemedicine/telehealth therapy; Private for-profit organization; State mental health department; The Joint Commission; Medicare; Medicaid; Private health insurance; Cash or self-payment; Clients with co-occurring mental and substance use disorders; Comprehensive mental health assessment; Comprehensive substance use assessment; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Aftercare/continuing care; Discharge Planning; HIV or AIDS education, counseling, or support; Substance use disorder education; Smoking/vaping/tobacco cessation counseling; Individual counseling; Group counseling; Family counseling; Marital/couples counseling; Smoking permitted in designated area; Children/adolescents; Female; Male; Sign language services for the deaf and hard of hearing; Vaping permitted in designated area; Case management service; Mental health services; Social skills development; Suicide prevention services