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; Accepts clients using medication assisted treatment for alcohol use disorder but prescribed elsewhere; No formal relationship with prescribing entity; Accepts clients using MAT but prescribed elsewhere; Brief intervention; Cognitive behavioral therapy; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Telemedicine/telehealth therapy; Private for-profit organization; State Substance use treatment agency; Federal, or any government funding for substance use treatment programs; Medicaid; Cash or self-payment; SAMHSA funding/block grants; Adolescents; Comprehensive substance use assessment; Interim services for clients; Screening for tobacco use; Screening for substance use; Aftercare/continuing care; Discharge Planning; Self-help groups; HIV or AIDS education, counseling, or support; Hepatitis education, counseling, or support; Substance use disorder education; Individual counseling; Group counseling; Family counseling; Smoking permitted in designated area; Children/adolescents; Female; Male; Vaping permitted in designated area