Objective: Cardiovascular endpoint trials are increasingly being performed in phase IV evaluations of antihypertensive, cholesterol-lowering, and glucose-lowering medications. To facilitate the conduct of economic evaluations in such studies, we developed a flexible tool to permit researchers to assign medical-care costs to events commonly included in cardiovascular endpoint trials. Methods: We used econometric techniques to fit generalized linear models to administrative data (Ingenix) on longitudinal costs of care for patients experiencing various cardiovascular events, including myocardial infarction, cardiac arrest, stroke (hemorrhagic & ischemic), transient ischemic event (TIA), revascularization procedures (CABG, PTCA, stenting), and various cardiovascular-related hospitalizations. Separate regression equations were estimated for patients who had these events as well as for their propensity-score matched controls. Costs of care (net of controls) were estimated on a monthly basis for the first 36 months following each event and then annually thereafter, with differences in survival between cases and controls factored into the longitudinal cost calculations. The regression models included covariates for age, sex, cardiovascular disease history, and comorbidity profile to permit differential estimation of event costs for patients of varying characteristics, as would be observed in cardiovascular endpoint trials. Results: Mean costs of care (2006 US$) for fatal events were $18,970 for MI, $12,630 for cardiac arrest, $19,830 for hemorrhagic stroke, and $11,930 for ischemic stroke. Mean costs over 36 months for nonfatal events were $36,370 for MI, $36,020 for resuscitated cardiac arrest, $59,270 for hemorrhagic stroke, $30,150 for ischemic stroke, $8,190 for TIA, $30,650 for CABG, and $27,780 for PTCA with stenting. Results differ by age, sex, and patient characteristics. Conclusion: The costing tool permits rapid assignment of medical-care costs to events occurring in cardiovascular endpoint trials. Widespread use of this tool will permit standardization of event costing in piggyback economic evaluations in endpoint trials as well as in cardiovascular modeling studies.