Substance use treatment; Treatment for co-occurring substance use plus either serious mental health illness in adults/serious emotional disturbance in children; Outpatient; Intensive outpatient treatment; Regular outpatient treatment; No formal relationship with prescribing entity; Does not use medication assisted treatment for alcohol use disorder; Accepts clients using MAT but prescribed elsewhere; Cognitive behavioral therapy; Substance use disorder counseling; 12-step facilitation; Private for-profit organization; State Substance use treatment agency; State department of health; Medicaid; Federal military insurance (e.g., TRICARE); Private health insurance; Cash or self-payment; State-financed health insurance plan other than Medicaid; Adolescents; Young adults; Adult women; Pregnant/postpartum women; Adult men; Seniors or older adults; Lesbian, gay, bisexual, transgender, or queer/questioning (LGBTQ); Veterans; 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; Outcome follow-up after discharge; Treatment for gambling disorder; Treatment for other addiction disorder; HIV or AIDS education, counseling, or support; Hepatitis 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; Seniors; Female; Male; Vaping permitted in designated area; Case management service; Domestic violence services, including family or partner; Mental health services; Social skills development