In recent decades, scientific literature has been rethinking the paradigms of regionalism, which will require the development of new models of macro-regional interaction. Despite the growing number of publications on the BRICS+ format, there is a lack of a comprehensive methodological framework capable of covering a variety of theoretical approaches and adapting them to the territorial specifics of the association. The purpose of the research is to develop a classification of methodological approaches to substantiating the essence of BRICS+ according to criteria: theoretical and cognitive foundations, and subject focus. In accordance with this, the tasks are set: to analyze and systematize key theoretical schools; to classify these approaches according to the stated criteria; to identify their strengths and weaknesses. The results revealed five groups of methodological approaches: classical theories of international relations; economic and structural; institutional; network and hybrid models; value-identical and critical paradigms. The analysis showed that none of them is able to fully reflect the complexity of BRICS+, which justifies the need for an interdisciplinary synthesis of structural, institutional, and cultural-constructivist analysis for further empirical verification and the development of practical recommendations for the development of the association. Of particular importance is the fact that the BRICS+ countries account for about a third of the world’s territory and almost half of the world’s population, and their combined contribution to GDP and foreign trade consistently exceeds the global average growth rate. At the same time, the association is characterized by the absence of a centralized management mechanism, which brings it closer to network models of cooperation and distinguishes it from classical integration blocks. This combination of factors reinforces the urgency of searching for a methodological framework for studying the essence of BRICS+ as a new type of global association.