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; 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; Contingency management/motivational incentives; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Trauma-related counseling; Telemedicine/telehealth therapy; 12-step facilitation; Private for-profit organization; Commission on Accreditation of Rehabilitation Facilities (CARF); The Joint Commission; Private health insurance; Cash or self-payment; Young adults; Adult women; Adult men; Clients with co-occurring mental and substance use disorders; 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; Naloxone and overdose education; Outcome follow-up after discharge; Self-help groups; Housing services; Assistance with obtaining social services; Mentoring/peer support; Employment counseling or training; HIV or AIDS education, counseling, or support; Hepatitis education, counseling, or support; Health education services other than HIV/AIDS or hepatitis; Substance use disorder education; Individual counseling; Group counseling; Family counseling; Smoking permitted in designated area; Adults; Young adults; Female; Male; Vaping permitted in designated area; Case management service; Social skills development; Transportation assistance