Long before the COVID‐19 pandemic, health‐care spending became a key policy issue across the OECD. Comparing recent institutional trends in public health‐care financing in three federal countries—Canada, the United States, and Mexico—this article explores the political struggles over fiscal federalism in health care related to both vertical and horizontal imbalances that can generate regional tensions and pit subnational governments against one another and, especially, against the national government. Grounded in a historical institutionalist perspective, the article shows how different institutional legacies shape current conflicts over federal health‐care funding in these three highly dissimilar federal countries. Such an analysis stresses the role of policy feedback in social politics and the enduring “varieties of federalism” in North American public health‐care funding. More specifically, the article shows how the distinct nature of policy feedback effects in the United States, Mexico, and Canada helps explain why the two former countries recently witnessed major changes in intergovernmental relations over fiscal federalism for health care while the latter did not.Related ArticlesBode, Ingo, and Jorge E. Culebro Moreno. 2018. “Paradoxical Internationalization: Regulatory Reforms in the Mexican Health‐Care System through the Lens of European Experience.” Politics & Policy 46(4): 678–710. https://doi.org/10.1111/polp.12268.Lauby, Fanny, and Christopher J. McKinley. 2023. “Factors of Early COVID‐19 Prevention Policy Engagement in France and the United States.” Politics & Policy 51(5): 830–48. https://doi.org/10.1111/polp.12556.Luccisano, Lucy, and Amy Romagnoli. 2007. “Comparing Public Social Provision and Citizenship in the United States, Canada, and Mexico: Are There Implications for a North American Space?” Politics & Policy 35(4): 716–51. https://doi.org/10.1111/j.1747‐1346.2007.00082.x.