Substance use treatment; Treatment for co-occurring substance use plus either serious mental health illness in adults/serious emotional disturbance in children; Outpatient; Outpatient day treatment or partial hospitalization; Does not use medication assisted treatment for alcohol use disorder; Does not use MAT for opioid use disorders; Medication for mental disorders; Anger management; Brief intervention; Cognitive behavioral therapy; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Trauma-related counseling; Telemedicine/telehealth therapy; Private for-profit organization; State Substance use treatment agency; State mental health department; State department of health; Federal, or any government funding for substance use treatment programs; IHS/Tribal/Urban (ITU) funds; Medicaid; Private health insurance; Cash or self-payment; State-financed health insurance plan other than Medicaid; Adolescents; Lesbian, gay, bisexual, transgender, or queer/questioning (LGBTQ); Clients with co-occurring mental and substance use disorders; Clients with HIV or AIDS; Clients who have experienced sexual abuse; Clients who have experienced intimate partner violence, domestic violence; Clients who have experienced trauma; Comprehensive mental health assessment; Comprehensive substance use assessment; Screening for substance use; Screening for mental disorders; Breathalyzer or blood alcohol testing; Drug or alcohol urine screening; Aftercare/continuing care; Discharge Planning; Outcome follow-up after discharge; HIV or AIDS education, counseling, or support; Hepatitis education, counseling, or support; Substance use disorder education; Individual counseling; Group counseling; Family counseling; Marital/couples counseling; Smoking not permitted; Adults; Children/adolescents; Young adults; Female; Male; Vaping not permitted; Mental health services; Social skills development; Transportation assistance; Suicide prevention services