OBJECTIVES Anaphylaxis is a rare yet potentially fatal allergic reaction. While at-risk patients are advised to carry self-injectable epinephrine with them at all times, many do not. We examined the costs and consequences of using an established device versus a novel device being developed by Intelliject, Inc. for treatment of a uniphasic anaphylactic reaction. Because of its smaller size and user-friendly design, the new device is expected to be carried and used correctly more often than the established device. METHODS A decision tree model for costs and consequences was created using DATA TreeAge 3.0. Consequences included recovering without visiting the emergency department (ED), ED use, and hospitalizations. Direct costs were estimated for device use, ED use, and hospitalizations. Data were obtained from the literature, HCUPnet (online query tool for Healthcare Cost and Utilization Project), and Intelliject's clinical study programs. For the purpose of this analysis, the price of the new device was assumed to be twice that of the established device. One-way sensitivity analyses were conducted for patients' probabilities of carrying the device and using it correctly and of recovery and death after using the device incorrectly. RESULTS Base case results per 100 patients indicate that the new device would lead to more patients recovering without visiting the ED (57 vs. 35), similar rates of ED use without hospitalization (7) and fewer hospitalizations (2 vs. 4). The results also indicate higher device costs ($15,837 vs. $6,291) and same ED use costs ($9375) but lower costs for hospitalizations ($15,303 vs. $30,606); leading to lower total costs for the new device ($40,515 vs. $46,272). Sensitivity analyses indicate that the new device would have lower total costs and lead to better consequences under most tested assumptions. CONCLUSIONS At the assumed price premium, the new device provided lower total costs, higher recovery rate as well as fewer hospitalizations.