The research proposes, as theme, to analyze the process of change in budgeting in the Legislative through the Joint Budget Committee - CMO, particularly the alterations in the institutional configuration of brazilian budgetary policy after redemocratization, assuming the new discursive institutionalism as a theoretical methodological guide. In this terms, the object of the research is the institutional adjustment in the CMO, focusing on the post-1988 period and its changing context. It seeks to answer the following questions: which ideational mechanisms affect the dynamics of the institutional design of the Joint Budget Committee - CMO? How was the process of change established in the CMO based on the critical scenario of redemocratization? Which discursive coalitions act on the institutional design and internal dynamics of the Joint Budget Committee - CMO? The research aims to identify the ideational mechanisms that act in the process of change in the Joint Budget Committee as an institution of Brazilian budgetary policy after the 1988 Constitution, understanding the relationship between institution, political agency and cognitive coalitions in the process of stabilization or policy alterations. Intensive Process Tracing is assumed as a methodological path, with the variation of theory-guided process tracing that enables a temporal and causal analysis of the sequences of events that constitute the process. Access to the database of documents related to public budgeting, its formatting in a textual corpus and further analysis, made it possible to understand that many ideals in tension after the promulgation of the 1988 constitution were already present in its initial debate and these ideas are looking for transmitters whether as a political agent or as a bureaucrat to infiltrate public policy spaces. The evidences demonstrate that the change after the redesign of budgetary policy in the context of redemocratization occurs gradually with the influence of two ideational mechanisms acting under the process of change in the CMO, these being the public philosophy and the decisional control mechanism, in addition, the coexistence between these two ideational mechanisms brings inaccurate institutional results, with an emptying of the CMO's planning action.