RESUMEN
A homeless mortality surveillance system identifies emerging trends in the health of the homeless population and provides this information to key stakeholders in a timely and ongoing manner to effect evidence-based, programmatic change. We describe the first 5 years of the New York City homeless mortality surveillance system and, for the first time in peer-reviewed literature, illustrate the impact of key elements of sustained surveillance (i.e., timely dissemination of aggregate mortality data and real-time sharing of information on individual homeless decedents) on the programs of New York City's Department of Homeless Services. These key elements had a positive impact on the department's programs that target sleep-related infant deaths and hypothermia, drug overdose, and alcohol-related deaths among homeless persons.