The history of creation of new professional accounting associations, mergers and proposed mergers among professional associations in Canada is reviewed through the lens of institutional theory to identify the conditions associated with major changes in the structure of the profession. Five waves of merger activity are identified between 1880 and 2010. These waves of mergers: (1) created isomorphism between the structure of accounting associations and the political structure of Canada, (2) differentiated associations to reflect the division of labour among accountants (primarily the separation of public and management accounting), (3) differentiated associations to reflect different educational paths into accounting (broadly conceived), and (4) consolidated the profession to facilitate the regulation of public accounting by the state. Contemporary issues affecting the structure of the profession are also identified including the globalization of accounting credentials. The historical waves of merger activity are argued to be an enactment of state and market institutional logics. These factors are compared with justifications/rationales and proposals for the merger of the accounting profession under the Chartered Professional Accountant, CPA, designation. The merger proposal would create a hybrid organization that retains within it historical institutional patterns. Issues concerning the stability of hybrid organizations in the literature are identified.