The purpose of this article is to describe the usability and human factors engineering standards used in development of a sepsis alert known as the sepsis prompt. Sensory processing, cognitive processing, signal detection, criterion response, and user satisfaction were evaluated with controlled user testing and critical incident response techniques. Nurses reported that the sepsis prompt was visible and distinct, making it easily detectable. The prompt provided a clear response mechanism and adequately balanced the number of false alerts with the likelihood of misses. Designers were able to use a mental model approach as they designed the prompt because the nurses were already using a manual sepsis detection process. This may have predisposed the nurses to response bias, and as such, they were willing to accommodate more false alarms than nurses who are not familiar with sepsis screening (surveillance). Nurses not currently screening for sepsis may not place the same value on this alert and find it an annoyance. The sepsis prompt met usability standards, and the nurses reported that it improved efficiency over the manual screening method.