This special issue of the Journal of Health Politics, Policy and Law centers on Nobel laureate Kenneth J. Arrow’s seminal article Uncertainty and the Welfare Economics of Medical Care. When the essay first appeared in 1963, health economics did not exist as an established field, and there was a professional and social bias against thinking about health care in economic terms. Arrow’s trailblazing article laid the foundation for modern health economics and has guided its direction for four decades. Now the Journal of Health Politics, Policy and Law examines this legacy, opening with a foreword by Mark V. Pauly, one of the first to publish a response to Arrow’s original article and a major voice in health economics today. A reprint of the article itself serves as a springboard from which contributors assess the accuracy of Arrow’s portrayal of the United States health care system in the early sixties and evaluate how the system has progressed since that time. The contributors to this remarkable collection include some of the most distinguished scholars in the health policy field. Designed to be an effective reference tool, this issue sets Arrow’s original article apart from the rest by printing it on tinted paper. The contributors’ responses to Arrow are divided into four parts-Part 1: Supply, Demand, and Health Care Competition; Part 2: Risk, Insurance, and Redistribution; Part 3: Information, Knowledge, and Medical Markets; Part 4: Social Norms and Professionalism.