At the first BRIC(S) summit in 2009, leaders of the major emerging market countries (Brazil, Russia, India, and China) from different continents committed to build a democratic and transparent economic architecture, support the efforts of the Group of 20 (G20) to reform the international financial institutions, restore growth, and deepen intra-group cooperation. Since then, views expressed in the literature on BRICS (expanded to include South Africa in 2010) have ranged from the harsh dismissal of BRICS as a meaningless investment banker’s acronym to its identification as a new power centre with a profound impact on the global economic order. The authors offer an updated, systematic assessment of BRICS’ evolving institutional dynamics, performance, and contribution to cooperation among its members, and to global governance as a whole. Using qualitative and quantitative methods, they identify the major achievements of each of the BRICS’ 13 annual summits through the three five-year hosting cycles, the leaders’ agreements on 933 collective commitments, and their countries’ compliance with them at a level of 77% overall. Further, they highlight the expansion of the group’s agenda into 34 subjects, the process of building the intra-BRICS institutions with the New Development Bank (NDB) as its hallmark, and its extensive second track networks including Business, Think Tanks and Academic, Trade Unions, Parliamentarian, Youth and Civil BRICS. In its first 15 years, BRICS expanded and sustained its institutional dynamics, depth, and performance despite external and domestic challenges, tensions between the members, and the unprecedented tests of the COVID19 pandemic and the ensuing socio-economic crises since 2020. Established as a dialogue and policy coordination forum, it matured into a transregional governance institution with a comprehensive political-security, socio-economic, and people-to-people agenda. Its dense institutional networks, flexibility, continuity, and foundational principle of moving forward only on issues acceptable to all members were vital factors for BRICS’ resilience and evolution. Although broadening its agenda inhibited deepening cooperation, there was considerable continuity across the annual presidencies. Progress on intra-BRICS cooperation was more tangible than that on international architecture reform, despite the group’s unwavering commitment to an equitable international order. Its consensus-based working methods sometimes constrained the group’s leadership. However, BRICS proved its value as a platform for facilitating its members’ bilateral relations and convergence in approaches, promoting their role in global governance, and advancing a more inclusive, representative, and effective international institutional system.