OBJECTIVES To examine the characteristics of patients diagnosed with atherosclerosis and describe the method of diagnosis and their management in a US managed care setting. METHODS Retrospective study utilizing administrative claims data from a US national health plan with >10 million commercial and Medicare Advantage members identified patients between March 31, 2005 and February 28, 2006, who were newly diagnosed with atherosclerosis (i.e., with no diagnosis of atherosclerosis and no history of cardiovascular events in the previous year). Patient demographics and Charlson comorbidity scores were computed. Lipid values and cardiac diagnostic tests were estimated one year pre- and post-diagnosis. RESULTS A total of 58,060 patients with newly diagnosed primary atherosclerosis were identified. The patient population was comprised of 60% men and 70% were > 50 years of age. The mean Charlson comorbidity score was 2.0, with 25% of patients with diabetes, 15% with COPD, and 7% with congestive heart failure. Approximately, 55% of patients were at high or moderate risk of coronary heart disease (CHD) based on National Cholesterol Education Program Adult Treatment Panel III guidelines. The majority of patients (45%) were managed by a cardiologist at the time of atherosclerosis diagnosis. Of patients with lipid value measures, mean LDL-C levels were 118 mg/dL pre-diagnosis and 113 mg/dL post-diagnosis. Less than 20% of patients with atherosclerosis had angiography, ultrasound or cardiac stress test within the year preceding diagnosis and 12% of all patients were tested <3 months prior to diagnosis. CONCLUSIONS Patients diagnosed with atherosclerosis were older, had more comorbidities and were more likely to be male. They had a moderate or high CHD risk and the majority was managed by cardiologists. Future similar research should focus on identifying distinguishing characteristics to facilitate identification of patients with atherosclerosis by health care providers.