BACKGROUND: The health care cost associated with myocardial infarction (MI) is highest the first year after an MI. However healthcare costs may continue to be high post MI for patients with stable CAD and at least one additional atherothrombotic risk factor. OBJECTIVES: To evaluate long term cardiovascular (CV) related and all cause healthcare costs in patients with stable CAD after MI and at least one additional atherothrombotic risk factors, resembling patients of the PEGASUS trial (NCT 01225562). METHODS: Health plan members, ≥ 50 years with no prior stroke, hospitalized with an MI diagnosis (index event) and MI free for 12 months (stable CAD) were identified from the HealthCore Integrated Research Environment, between 01/2007 and 11/2011. Rates of MI and stroke hospitalizations during a 2-year follow-up were calculated. CV related and all cause healthcare costs were evaluated per patient. Hospitalization rates and healthcare costs were only evaluated in patients <65 years due to data and population limitations in the database. RESULTS: Of 13 492 stable CAD patients identified, 5357 met the PEGASUS inclusion criteria with at least one additional atherothrombotic risk factor (≥1 prior MI, diabetes or chronic non end-stage renal disease). The MI and stroke related hospitalization rates for patients with stable CAD and fulfilling the PEGASUS criteria at 2 years post index event, were 7.7% and 2.5%, respectively. The CV related and all cause healthcare cost per patient year during the follow up period were $15 247 and $26 073 for patients with and $7 521 and $13 566 for patients without at least one additional atherothrombotic risk factor. CONCLUSIONS: The economic burden post MI for patients below 65 years with stable CAD and at least one additional atherothrombotic risk factor in a US managed care population is substantial several years following an MI.