Although the principles of healthcare economics are not usually part of the fundamental education of emergency physicians, an understanding of these elements will enhance our ability to contribute to improved health-care value. This article introduces the practical aspects of microeconomics, insurance, the supply-and-demand relationship, competition, and costs as they affect the practice of medicine on a daily basis. Being cognizant of how these elements create a dynamic interplay in the health-care industry will allow physicians to better understand the expanded role they need to assume in the ongoing cost and quality debate. (Am J Emerg Med 2003;21:55-60.