Since the 1980s, regulated markets and New Public Management have been introduced in the public sector across the world. How they have affected existing governance mechanisms such as self-regulation and state regulation has remained largely unexplored, however. This article examines the origins and consequences of institutional layering in governing healthcare quality. Dutch health care, where a market-based system has been introduced, is used as a case study. The results show that this market-based system did not replace but modified existing institutional arrangements. As a result, hospitals have to deal with the fragmentation of quality demands. Using the concept of institutional layering, this study shows how different arrangements interact. As a consequence, the introduction of a certain policy reform will work out differently in different countries and policy sectors. Our ‘archaeological’ study in this layering can be seen as an example of how such incremental change can be studied in detail.