OBJECTIVES Although laboratory testing is essential for the diagnosis, pharmacotherapy, and monitoring of anemia, inefficient utilization of laboratory resources may increase the cost-of-treatment of anemia without improving clinical outcomes. Of particular concern is the ordering of redundant tests incapable of providing important information for treatment when clinically significant changes in biochemical outcomes do not occur over short periods of time. Bundling of tests into diagnostic categories on order forms may cause such overutilization. The objective of this study was to determine whether unbundling of order-sets on a computerized order-form can reduce the number of suspected unnecessary blood tests for folic acid and vitamin B-12 ordered by primary care physicians in a managed care organization in Israel. METHODS This study was conducted in the Leumit Health Fund of Israel that provides medical coverage to ~700,000 members nationally. A new version of a computerized order form was launched. Utilization patterns were calculated for tests for vitamin B-12, folic acid and ferritin which were previously bundled together under a collective diagnostic classification category labeled “Anemia” and now appearing separately. Concomitant utilization patterns for tests for hemoglobin and iron were evaluated as controls. RESULTS Tests ordered for the three target tests decreased by 31%-41% relative to the preintervention month, with a further decrease to 36%-53% the following month. Negligible changes in utilization patterns were observed for the controls (-2%-3%) during the post-intervention period. CONCLUSIONS Restructuring of a computerized order-form significantly reduced the number of lab tests suspected of being unnecessary or redundant. We cannot rule out that some patients with folate deficiency may not have been identified after unbundling the tests due to the additional inconvenience caused to physicians who now had to order tests separately. When over-utilization of laboratory resources is suspected, restructuring of ordering procedures should be considered prior to implementing resource-intensive interventions.