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; Outpatient methadone/buprenorphine or naltrexone treatment; Regular outpatient treatment; Buprenorphine used in Treatment; Naltrexone used in Treatment; Does not treat alcohol use disorder; Buprenorphine maintenance; Buprenorphine maintenance for predetermined time; Prescribes buprenorphine; Prescribes naltrexone; Relapse prevention with naltrexone; Acamprosate (Campral®); Disulfiram; Buprenorphine sub-dermal implant; Buprenorphine with naloxone; Buprenorphine without naloxone; Buprenorphine (extended-release, injectable); Naltrexone (oral); Naltrexone (extended-release, injectable); Medications for Hepatitis C treatment; Lofexidine; Clonidine; Medication for mental disorders; Nicotine replacement; Non-nicotine smoking/tobacco cessation; Brief intervention; Cognitive behavioral therapy; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Telemedicine/telehealth therapy; Trauma-related counseling; 12-step facilitation; Private non-profit organization; State Substance use treatment agency; State mental health department; State department of health; Commission on Accreditation of Rehabilitation Facilities (CARF); Federal, or any government funding for substance use treatment programs; Medicare; Medicaid; Private health insurance; Cash or self-payment; Sliding fee scale (fee is based on income and other factors); Adolescents; Young adults; Adult women; Pregnant/postpartum women; Adult men; Seniors or older adults; Lesbian, gay, bisexual, transgender, or queer/questioning (LGBTQ); Veterans; Criminal justice (other than DUI/DWI)/Forensic clients; Clients with co-occurring mental and substance use disorders; Clients with co-occurring pain 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; Interim services for clients; Outreach to persons in the community; Complete medical history/physical exam; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Breathalyzer or blood alcohol testing; Drug and alcohol oral fluid testing; Drug or alcohol urine screening; HIV testing; STD testing; TB screening; Metabolic syndrome monitoring; Testing for Hepatitis B (HBV); Testing for Hepatitis C (HCV); Aftercare/continuing care; Discharge Planning; Naloxone and overdose education; Outcome follow-up after discharge; Self-help groups; Housing services; Assistance with obtaining social services; Recovery coach; Mentoring/peer support; Employment counseling or training; Treatment for other addiction disorder; 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; Smoking/vaping/tobacco cessation counseling; Individual counseling; Group counseling; Family counseling; Hepatitis A (HAV) vaccination; Hepatitis B (HBV) vaccination; Smoking not permitted; Children/adolescents; Seniors; Female; Male; Spanish; Vaping not permitted; Case management service; Early intervention for HIV; Mental health services; Social skills development; Transportation assistance; Integrated primary care services