BACKGROUND: Febrile infants commonly present to emergency departments for evaluation. OBJECTIVE: We describe the variation in diagnostic testing and hospitalization of febrile infants =60 days of age presenting to the emergency departments in the Pediatric Emergency Care Applied Research Network. METHODS: We enrolled a convenience sample of non-critically ill-appearing febrile infants (temperatures >/=38.0 degrees C/100.4 degrees F) =60 days of age who were being evaluated with blood cultures in 26 Pediatric Emergency Care Applied Research Network emergency departments between 2008 and 2013. Patients were divided into younger (0-28 days of age) and older (29-60 days of age) cohorts for analysis. We evaluated diagnostic testing and hospitalization rates by infant age group using chi-square tests and by site using analysis of variance. RESULTS: Four thousand seven hundred seventy-eight patients were eligible for analysis, of whom 1517 (32%) were 0-28 days of age. Rates of lumbar puncture and hospitalization were high (>90%) among infants =28 days of age, with chest radiography (35.5%) and viral testing (66.2%) less commonly obtained. Among infants 29-60 days of age, lumbar puncture (69.5%) and hospitalization (64.4%) rates were lower and declined with increasing age, with chest radiography (36.5%) use unchanged and viral testing (52.7%) slightly decreased. There was substantial variation between sites in the older cohort of infants, with lumbar puncture and hospitalization rates ranging from 40% to 90%. CONCLUSIONS: The evaluation and disposition of febrile infants =60 days of age is highly variable, particularly among infants who are 29-60 days of age. This variation demonstrates an opportunity to modify diagnostic and management strategies based on current epidemiology to safely decrease invasive testing and hospitalization.