This study explores whether the implementation of sustainability disclosure can trigger or stimulate the change in the roles of management accountants in adopting organizations in Vietnam as business partners. To do so, it explores the roles of management accountants in integrated reporting (IR) adopting organizations and sustainability reporting (SR) adopting organizations based on the use of the pragmatic constructivism (PC) theoretical framework. In addition, qualitative semi-structured interviews were used to provide an in-depth investigation of management accountants’ work in both IR and SR adopting organizations. The empirical findings suggest that the adoption of the IR framework has triggered changes in management accountant roles toward the new business partner roles to support the decision-making process within their organizations. On the other hand, management accountants from SR adopting organizations still work as traditional “bean-counter” roles. Our paper concludes by indicating several propositions based on our empirical findings that can be tested by future researchers from the domain by collecting relevant data. Our study can be seen as a response to the recent call for a more in-depth examination of the practice of sustainability disclosure from the practitioners’ perspectives in adopting organizations.