Substance use treatment; Outpatient; Intensive outpatient treatment; Regular outpatient treatment; Naltrexone used in Treatment; No formal relationship with prescribing entity; Does not treat alcohol use disorder; Prescribes naltrexone; Accepts clients using MAT but prescribed elsewhere; Naltrexone (oral); Naltrexone (extended-release, injectable); Private non-profit organization; State Substance use treatment agency; State department of health; The Joint Commission; Private health insurance; Cash or self-payment; Adult women; Adult men; Veterans; Active duty military; Comprehensive substance use assessment; Screening for tobacco use; Screening for substance use; Breathalyzer or blood alcohol testing; Drug and alcohol oral fluid testing; Drug or alcohol urine screening; Aftercare/continuing care; Discharge Planning; Naloxone and overdose education; Outcome follow-up after discharge; Self-help groups; Assistance with obtaining social services; 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 not permitted; Case management service; Domestic violence services, including family or partner; Mental health services