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; Clonidine; Medication for mental disorders; Cognitive behavioral therapy; Contingency management/motivational incentives; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Telemedicine/telehealth therapy; Trauma-related counseling; Private non-profit organization; State Substance use treatment agency; State mental health department; State department of health; Council on Accreditation (COA); Medicaid; Private health insurance; Cash or self-payment; Sliding fee scale (fee is based on income and other factors); Adolescents; Young adults; Lesbian, gay, bisexual, transgender, or queer/questioning (LGBTQ); Clients with co-occurring mental and substance use disorders; Clients who have experienced trauma; Comprehensive mental health assessment; Comprehensive substance use assessment; Interim services for clients; Outreach to persons in the community; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Drug or alcohol urine screening; Aftercare/continuing care; Discharge Planning; Outcome follow-up after discharge; Housing services; Assistance with obtaining social services; Substance use disorder education; Smoking/vaping/tobacco cessation counseling; Individual counseling; Group counseling; Family counseling; Smoking not permitted; Adults; Children/adolescents; Young adults; Female; Male; Sign language services for the deaf and hard of hearing; Vaping not permitted; Case management service; Domestic violence services, including family or partner; Mental health services; Social skills development; Suicide prevention services