Three issues have dominated national health policy discussions over the past three decades–how to control health expenditures, how to improve access to care, and how to ensure delivery of high-quality health services. Cost remains the principal societal concern today. An important new dimension in this debate, however, is a critical examination of the impact of the structure of the nation’s health workforce on health expenditures. Within this examination, policy makers are giving specific attention to the supply of health professionals, the role of primary care, and the identification of the most appropriate professionals to deliver primary care. In particular, a renewed interest is being shown in the potential of physician assistants (PAs) and nurse practitioners (NPs) to address all three issues. This article will examine the factors that prompted this focus on health workforce issues and the implications of the use of PAs and NPs for the structure and management of the health workforce in the future.