In political discourse, the term “single-payer system” originated in an attempt to stake out a middle ground between the public and private sectors in providing universal access to health care. In this view, a single-payer system is one in which health care is financed by government and delivered by privately owned and operated health care providers. The term appears to have been coined in U.S. policy debates to provide a rhetorical reference point for universal health insurance other than the “socialized medicine” of state-owned and -operated health care providers. This article, like others in this special issue, is meant to provide a more nuanced view of singe-payer systems. In particular, it reviews experience in the prototypical single-payer system for physician and hospital services: the Canadian case. Given Canada's federal governance structure, this example also aptly illuminates the scope and limits of subnational variation within this single model of health care finance. And what it demonstrates in essence is that the very feature that defines the single-payer prototype—the maintenance of independent providers remunerated by a single public payer in each province—also leads to a set of profession-state bargains that define the limits of variation.