Guidelines from the National Cholesterol Education Program (NCEP) recommend reduction of low-density lipoprotein cholesterol (LDL-C) to 100 mg/dL (2.59 mmol/L) or less in patients with established coronary heart disease (CHD). However, the National Committee for Quality Assurance (NCQA) is implementing a new performance measure as part of the Health Plan Employer and Data Information Set (HEDIS) that appears to endorse a different target. The new HEDIS measure will require managed care organizations seeking NCQA accreditation to measure and report the percentage of patients who have had major CHD events who achieve LDL-C levels less than 130 mg/dL (3.36 mmol/L) between 60 and 365 days after discharge. These different LDL-C thresholds emphasize the difference between a clinical goal for the management of individual patients (< or =100 mg/dL) and a performance measure used to evaluate the care of a population of patients (<130 mg/dL). This article discusses the rationale for each threshold and explains the use of 2 different thresholds for these 2 purposes. Both the NCQA and NCEP expect that the new HEDIS measure will encourage managed care organizations to develop systems that improve secondary prevention of CHD.