Universal healthcare does not look the same everywhere: Divergent experiences with the private sector in Brazil and Thailand.

How does the private sector structure the trajectory of a country's universal healthcare programme? Social scientists have long pointed to the importance of path dependence in shaping health reform. Yet, rarely have middle-income countries' experience with the private sector under Universal Health Coverage (UHC) been examined from comparative perspective. In this paper, we explore the changing landscape of the health sector in Brazil and Thailand before UHC reform and after. We find path-dependent processes at work that have pushed two countries that both adopted UHC reforms in divergent directions. In Brazil, a comparatively large and entrenched private sector that existed before reform has grown over time, and a sizable private health insurance industry has exerted powerful influence on health policy, weakening the public sector. In Thailand, constraints on private health insurance growth and sustained investment in public health infrastructure and governance have helped check the growth of private sector influence, although battles over health policy still remain contentious. The experiences of these countries offer lessons for policymakers seeking to achieve and maintain robust UHC programmes in other contexts.