Because of its early positive assessments, participatory budgeting (PB) has been and continues to be praised by several policymakers, and the Brazilian model has become an institutional blueprint around the world. No one questions the way the model has evolved in Brazilian municipalities with a long tradition of PB, but it was institutionalized there through practice and not through state legislation. It is thus highly permeable to political will and evolving ideas. Looking at the case of Belo Horizonte, where it was implemented in 1993, this study argues that while the political rhetoric of PB has remained central to political discourse over time, a significant but gradual policy change has occurred in practice. This change has important implications: not only does it have an impact on the policy outcomes of PB, but it also contributes to delegitimating the process for its participants, abetting its gradual deinstitutionalization.