Much analysis of health care markets draws heavily on the experiences of the advanced market economies where there is a much clearer demarcation of the roles of, and boundaries between, the public and private sectors in delivering services. This has led to a tendency to seek models for ―working with the private sector‖ from these countries, without taking sufficient account of their strong institutional and regulatory arrangements for both market and non-market services (Bloom and Standing 2008). This paper argues for a different approach to policy formulation that bases the assessment of the likely outcome of different reform options on a closer understanding of the realities of the markets that have emerged in developing and transitional economies. It has two main aims: The first is to develop an exploratory framework for understanding how health markets operate in these contexts, using primarily a political economy rather than a public health approach to health systems. The argument here rests on our view that theoretical perspectives grounded in an understanding of the dynamics of markets and their interplay with different contextual conditions offer fresh insights for health systems development. The second is to begin to lay out the implications of these different ways of thinking about health markets for policies and programs. This points us away from standard health policy approaches to planning and regulation and toward questions of knowledge transfer and learning in highly dynamic environments.