Research Originality: This study assesses Indonesia's move to join the BRICS as a pragmatic economic strategy through an efficiency analysis and an empirical comparison. Data Envelopment Analysis (DEA) is used to measure government spending efficiency, and panel data analysis is used to compare fiscal performance across BRICS countries. Research Objectives: The research seeks to analyze how government effectiveness (GE), corruption perception index (CPI), trade openness (TO), and industrial value added (IND) shape government spending efficiency (GSE) across BRICS countries during the 2000–2023 period. Research Methods: A two-stage approach is used: DEA estimates fiscal efficiency, while panel regression identifies its determinants. Empirical Results: Empirical findings reveal that Indonesia consistently maintained strong fiscal efficiency, outperforming several original BRICS members even prior to its accession. The determinants of efficiency varied between periods: from 2000 to 2009, GE, CPI, and TO positively influenced GSE, while IND had a negative association. In contrast, from 2010 to 2023, GE and TO exerted adverse effects. Implications: These findings suggest that maintaining fiscal efficiency in Indonesia depends on enhancing governance quality and strengthening industrial competitiveness. JEL Classification: C67, H11, H50 How to Cite:Bistyantri, N. B., & Kurniasih, L. (2026). Government Spending Efficiency in BRICS Countries: Implications for Indonesia’s Accession. Signifikan: Jurnal Ilmu Ekonomi, 15(2), 437-452. https://doi.org/10.15408/sjie.v15i2.46845.