The enactment of Law No. 15,484/2026 represents one of the most significant changes to the Brazilian appellate system since the entry into force of the 2015 Code of Civil Procedure (CPC). By regulating the requirement of relevance for federal non-constitutional legal issues as a condition for the admissibility of a Special Appeal (Recurso Especial), the legislature has implemented the innovation introduced by Constitutional Amendment No. 125/2022 and inaugurated a new phase in the role of the Superior Court of Justice (STJ).
The new legislation introduced Article 1,035-A into the Code of Civil Procedure, establishing the procedure for assessing the relevance of federal legal issues. Among other measures, it now requires appellants to demonstrate, in a specific section of the Special Appeal, that the controversy presents economic, political, social, or legal relevance that transcends the subjective interests of the parties. The law also provides that the absence of relevance may only be recognized by a vote of two-thirds of the members of the adjudicating panel, reinforcing the exceptional nature of dismissing an appeal on this ground.
The reform, however, goes beyond creating a new admissibility requirement. Law No. 15,484/2026 amended several provisions of the Code of Civil Procedure to align the entire appellate system with the new model. Of particular importance is the amendment to Article 927, which now includes decisions rendered under the relevance regime among Brazil’s binding precedents. Additional changes to Articles 932, 979, 988, 998, 1,030, and 1,039 of the CPC demonstrate that the legislature’s concern extends beyond the admission of Special Appeals and encompasses the broader precedential effects these decisions will have throughout the legal system.
Perhaps this is the most significant aspect of the reform.
Much has been said about Law No. 15,484/2026 creating a new admissibility requirement for the Special Appeal. While this is true, such a statement does not fully capture the extent of the transformation. In practice, the new framework alters the very logic underlying the structure of a Special Appeal, introducing what may be described as a dual foundation of appellate argumentation.
Until now, appellants were required to persuade the STJ that the challenged decision violated federal law. This remains the core purpose of the Special Appeal. Going forward, however, that will no longer be sufficient. Litigants must also convince the Court that the issue possesses sufficient relevance to justify the STJ’s institutional intervention.
In other words, two distinct and equally indispensable demonstrations now coexist.
The first concerns the legal error allegedly committed by the lower court decision.
The second concerns the institutional importance of the controversy for the uniform interpretation of federal law.
Although related, these are autonomous inquiries that answer different questions. The first seeks to explain why the challenged decision is legally incorrect. The second seeks to demonstrate why correcting that error matters to the Brazilian legal system as a whole.
This distinction profoundly changes the way Special Appeals must be drafted.
Previously, appellate arguments focused on interpreting federal statutes, demonstrating legal violations, establishing prior consideration of the issue (prequestionamento), and, where applicable, proving conflicting case law. Under the new regime, appellants must also construct an institutional narrative capable of demonstrating why the controversy extends beyond the interests of the parties and deserves review by the Superior Court of Justice.
For this reason, the demonstration of relevance can hardly be treated as a merely formal requirement or satisfied through standardized formulas.
In some cases, relevance will stem from the existence of a large number of proceedings involving the same legal issue. In others, it may arise from conflicting case law, significant economic consequences for a productive sector, impacts on public administration, or the need to stabilize the interpretation of federal legislation. Each controversy will require its own justification, developed from the particulars of the case and the institutional repercussions of the issue under debate.
From this perspective, Law No. 15,484/2026 strengthens a trend that has become increasingly evident in recent years: the consolidation of the Superior Court of Justice as a true precedent-setting court.
The amendment to Article 927 of the CPC is particularly significant in this regard. It demonstrates that decisions rendered under the relevance regime will formally become part of Brazil’s system of binding precedents, thereby expanding their capacity to guide the uniform interpretation of federal law throughout the country.
Naturally, it will be up to the STJ itself to define, through its case law, the practical contours of the concept of relevance. The development of these parameters will be essential to ensure predictability, legal certainty, and equal treatment of litigants, preventing an open-ended legal concept from being applied inconsistently on a case-by-case basis.
Law No. 15,484/2026 therefore represents much more than the regulation of a new constitutional filter. It fundamentally transforms the way Special Appeals are conceived and structured.
Appellants will continue to bear the burden of demonstrating a violation of federal law, but this alone will no longer suffice. They must also present a consistent and persuasive explanation as to why resolving the controversy contributes to the development of national case law and the uniform interpretation of federal legislation.
The Special Appeal thus becomes an even more technical procedural instrument.
Appellate advocacy will be required to develop more sophisticated arguments, capable of demonstrating not only that the challenged decision is incorrect, but also that the matter possesses institutional relevance worthy of judicial review.
The technical excellence that has always distinguished legal practice before the STJ is now subject to even higher standards. Ultimately, the success of a Special Appeal will depend not only on proving a violation of federal law, but also on persuading the Court that the issue deserves to become part of the body of precedents shaping the interpretation of Brazilian federal law.
The new framework will enter into force 30 days after the official publication of Law No. 15,484/2026, which occurred on August 4, 2026. This transitional period should be used by lawyers, judges, and other legal professionals to understand the profound changes that will govern the admissibility and adjudication of Special Appeals moving forward.
Available at: https://www.migalhas.com.br/depeso/461841/o-filtro-da-relevancia-no-stj-e-a-dupla-fundamentacao-do-recurso
Autor: Daniel Feitosa Naruto • email: daniel.naruto@ernestoborges.com.br
