This essay reviews and evaluates recent comparative social science scholarship on healthcare systems. We focus on four of the strongest themes in current research: (1) the development of typologies of healthcare systems, (2) assessment of convergence among healthcare systems, (3) problematization of the shifting boundaries of healthcare systems, and (4) the relationship between healthcare systems and social inequalities. Our discussion seeks to highlight the central debates that animate current scholarship and identify unresolved questions and new opportunities for research. We also identify five currents in contemporary sociology that have not been incorporated as deeply as they might into research on healthcare systems. These five “missed turns” include an emphasis on social relations, culture, postnational theory, institutions, and causal mechanisms. We conclude by highlighting some key challenges for comparative research on healthcare systems.