We describe a collaboration between a health system and public health department to create a mortality surveillance system. The collaboration enabled the health system to identify more than six times the number of deaths identified through local system medical records alone. This powerful epidemiological process, combining the nuanced data captured through clinical care in health systems with subsequent data on mortality, drives quality improvement, scientific research, and epidemiology that can be of particular benefit to underserved communities. (Am J Public Health. 2023;113(9):943-946. https://doi.org/10.2105/AJPH.2023.307335).