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; Motivational interviewing; Substance use disorder counseling; Trauma-related counseling; Telemedicine/telehealth therapy; Private non-profit organization; State mental health department; Private health insurance; Cash or self-payment; Sliding fee scale (fee is based on income and other factors); Adolescents; Clients with co-occurring mental and substance use disorders; Clients who have experienced trauma; Outreach to persons in the community; Screening for substance use; Screening for mental disorders; Aftercare/continuing care; Substance use disorder education; Individual counseling; Group counseling; Family counseling; Smoking not permitted; Children/adolescents; Female; Male; Spanish; Vaping not permitted; Case management service; Mental health services; Social skills development; Suicide prevention services