Accurate measurement of adverse event rates is critical to patient safety improvement efforts. This study used 2018 mortality data and ICD-10-CM codes to characterize adverse event deaths in the United States compared to non-adverse event deaths. The author estimates that 0.16-1.13% of deaths are attributed to an adverse event. Procedure-related complications contributed to the majority of adverse event deaths. The risk of death due to adverse event was higher for younger patients and Black patients.