epsis is both the most expensive condition treated and the most common cause of death in hospitals in the United States. [1][2][3] Most sepsis patients (as many as 80% to 90%) meet sepsis criteria on hospital arrival, but mortality and costs are higher when meeting criteria after admission. [3][4][5][6] Mechanisms of this increased mortality for these distinct populations are not well explored. Patients who present septic in the emergency department (ED) and patients who present as inpatients likely present very different challenges for recognition, treatment, and monitoring. 7 Yet, how these groups differ by demographic and clinical characteristics, the etiology and severity of infection, and patterns of resuscitation care are not well described. Literature on sepsis epidemiology on hospital wards is particularly limited. 8 This knowledge gap is important. If hospital-presenting sepsis (HPS) contributes disproportionately to disease burd-CHFens, it reflects a high-yield population deserving the focus of quality improvement (QI) initiatives. If specific causes of disparities were identified-eg, poor initial resuscitation-they could be specifically targeted for correction. Given that current treatment guidelines are uniform for the two populations, 9,10 characterizing phenotypic differences could also have implications for both diagnostic and therapeutic recommendations, particularly if the groups display substantially differing clinical