The re-engineering of health care by both government and private sector efforts is dramatically changing the appearance and function of medicine. Health providers are seeking partners, stimulated by the goals of managed care organizations (MCOs) to control cost and to increase market share through regionalization of their products. Ventures between even the most unlikely of providers are developing to gain potential savings by greater economies of scale, extending services and increased regional coverage. Because of the complex nature of this process, laboratory management faces a variety of developing models under which they must operate. Pathologists face the same change. The basic elements of pathology practice change associated with integration are similar to those for hospitals (1). Integration brings with it the opportunity for cost reduction, increased market share, standardization of methods and reports, broadened services, combined infrastructure, and a contracting advantage (2). The following is a discussion of integrated delivery systems and the impact on the laboratory operation.