Xylazine’s role in fatal overdose and adverse health outcomes are raising concerns for health providers who care for people who use drugs. As fentanyl shifted from being an occasional contaminant of heroin to replacing it altogether, drug surveillance shows that as of this program’s date, xylazine is now the primary drug adulterant in Philadelphia. This session describes what is know about xylazine and explore questions related to medical care for patients who have substance use disorder.