This article introduces a special issue of Medical Anthropology Quarterly on health insurance and health reform. We begin by reviewing anthropological contributions to the study of financial models for health care and then discuss the unique contributions offered by the articles of this collection. The contributors demonstrate how insurance accentuates—but does not resolve tensions between granting universal access to care and rationing limited resources, between social solidarity and individual responsibility, and between private markets and public goods. Insurance does not have a single meaning, logic, or effect but needs to be viewed in practice, in context, and from multiple vantage points. As the field of insurance studies in the social sciences grows and as health reforms across the globe continue to use insurance to restructure the organization of health care, it is incumbent on medical anthropologists to undertake a renewed and concerted study of health insurance and health systems.