This paper explores the role of history and agency in new institutional theory (NIT). The themes of history and agency in NIT are examined through a case study of the use of rhetorical strategies in introducing Medicare in the United States (U.S.). The study is empirically grounded in archival research, involving an analysis of over 9,590 pages of congressional hearings on Medicare covering the period 1958–1965. In the process, the paper contributes to three major debates: the historic turn in management and organization studies (MOS); NIT and agency; and rhetoric and organizational legitimacy.