O article reviews the legal and political process mobilised in search of discretionary power over the spending of the State Health Fund budget. This is a dispute in the STF expressed in ADI 2999 (State of Rio de Janeiro X National Health Council) and ADI 3088 (PSDB X State of Rio de Janeiro). The analysis of ADI was carried out on the basis of a qualitative focus by analysing rhetoric. In addition, we followed four methodological steps to analyse court cases: (1) analysis of the background to the case; (2) an analysis of the legal basis; (3) the monitoring of the construction of the decision; and (4) the assessment of the effectiveness of the decision. The study showed that the main issue in IDA was a federal conflict in which the State of Rio de Janeiro took the lead in deciding on health spending. It follows that the action of the STF makes it possible to address the need for judicial review not only by means of the effects of the decisions present in the judgments, but also by the dispute of arguments in the actions and the mobilisation of the Legislator and the Executive.