OBJECTIVES: Infective endocarditis (IE) is one of the most common hospital-acquired infections. This study used Medicare claims data to understand the current hospital-acquired infective endocarditis (HAIE) burden and associated risk factors. METHODS: The analysis was conducted using 2011 and 2012 Centers for Medicare and Medicaid Services Part A fee-for-service claims.  Patients with an IE ICD-9 diagnosis code in 2012 and at least 6-months of follow-up were included. HAIE was defined as IE with 1) onset ≥72 h after admission or 2) a significant invasive procedure performed during a hospitalization ≤ 8 weeks before the onset. To measure the impact of HAIE versus non-HAIE on medical costs, a generalized estimating equation approach with a gamma distribution and log link function was used. Logistic regression was used to assess patient demographics’ and comorbidities’ association with HAIE. RESULTS: