Brought to fame by a 1994 World Bank report, the idea of pension pillarization has become part of the orthodoxy of pension reform. Yet scholars have neglected both the national origins and the pre-1994 diffusion of the ‘three-pillar doctrine’. This article presents a critical history of the transnational diffusion process that led to the adoption of this concept at the World Bank. My analysis retrieves the Swiss roots of the doctrine during the late 1960s, as well as its gradual adoption and mainstreaming during the 1970s and early 1980s by a transnational epistemic community of life insurers and pension consultants. By 1990, the doctrine was widely used without reference to its national origins: a Swiss trademark had become a generic reform idea that framed controversies on the future shape of old-age provision.