ObjectiveTo estimate long-term mortality and medical care charges among patients with severe sepsis.DesignRetrospective cohort study.SettingLarge, integrated, geographically diverse, U.S. health-insurance claims database covering three million lives annually.PatientsAll persons with bacterial or fungal infections and acute organ dysfunction (severe sepsis) who were hospitalized between January 1, 1991, and August 31, 2000.InterventionsNone.Measurements and Main ResultsAll patients were followed from the date of hospitalization with severe sepsis (index admission) to August 31, 2000, disenrollment from the health plan, or death, whichever occurred first. Measures of interest included mortality and medical care charges and were estimated for the index admission, the 90- and 180-day periods following the index admission, and annually thereafter (up to 5 yrs), using techniques of survival analysis. A total of 16,019 patients were identified who met study entrance criteria. Most patients (81.2%) were ≥65 yrs of age; 53.4% were men. Mortality was 21.2% for the index admission, 51.4% at 1 yr, and 74.2% at 5 yrs. Mean cumulative total medical care charges were $44,600 for the index admission, $78,500 at 1 yr, and $118,800 at 5 yrs. Hospitalization accounted for the largest component of total medical care charges.ConclusionsMortality and economic costs are high in patients with severe sepsis, during the period of acute illness as well as subsequently.