BACKGROUND: Previous studies have suggested that epinephrine auto-injector (EAI) carriage and emergency use practices could be suboptimal for patients prescribed these devices for anaphylaxis management. OBJECTIVE: To characterize EAI prescription fill rates, carriage, and use practices and associated factors and perceived barriers to recommended anaphylaxis management behaviors in US children, adolescents, and adults. METHODS: Survey data were collected for adults (n=450) and parents of children (n=255) and adolescents (n=212) who had been prescribed an EAI. Of eligible participants, survey completion rates were higher than 90%. A multiple-group structural equation model was fit to test adjusted associations. RESULTS: Most patients (89%) filled their EAI prescriptions; however, of those who did not, the most commonly cited barriers to filling prescriptions were no history of reactions (26%) and EAI cost (25%). Forty-four percent carried at least 1 EAI "all the time" and 24% carried multiple EAIs. Sixty-five percent of respondents reported a personal history of EAI use. Most adults (52%) reported that an EAI was not used, although it would have been beneficial during their most severe allergic reaction. The most frequently given reasons for not using an EAI among respondents owning one were that an EAI was not available (45%) followed by their allergy was undiagnosed at the time (35%). To improve clinical anaphylaxis management, 61% of patients desired more effective patient education and 47% desired more time dedicated to patient education during the physician visit. CONCLUSION: These data suggest that current anaphylaxis management practices are suboptimal but could be facilitated through lowering EAI-related out-of-pocket costs and improving patient education efforts.