Health and its distribution are the focus of important issues for political philosophy. We begin with the basic question, “What is health?” (Section 2). Although some definitions tend to conflate health with all of well-being, one narrower definition that we use in what follows, in part because it fits well with actual work in epidemiology, public health, and health policy, remains controversial. One point of controversy is that some believe the narrow conception excludes a broad view of the answer to our second question, “What are the sources of population health and its distribution?” (Section 3). This belief is mistaken, for the narrower definition of health can be combined with a broad view of the causes of health, an important point because it turns out that social justice is actually good for our health. This fact about justice and health requires us to consider more carefully our third question, “What do we owe each other by way of protecting and promoting population health and distributing it fairly?” (Section 4). Though different accounts of justice answer this question in different ways, we concentrate on the implications of one liberal egalitarian view that extends Rawls’s account of justice as fairness. Though this theory gives us some guidance in thinking about what we owe each other, it leaves considerable room for reasonable disagreement about how to incorporate in health policy two key objectives: improving population health and distributing that health fairly. This reasonable disagreement raises our fourth question, “How can we meet health needs fairly when we cannot meet them all?” (Section 5). After canvassing some options, we consider how one proposal that draws on democratic deliberative theory addresses, and we conclude by providing an answer to, a fifth question, “How should we understand a right to health or health care?” (Section 6).