Abstract. Purpose — This paper introduces and validates the ICRC (ISSAI Conformity and Reform Capability) index — a novel multi-dimensional methodological framework for assessing the compliance of Supreme Audit Institutions (SAIs) with INTOSAI's International Standards (ISSAI). The framework is specifically designed for medium-sized SAIs in transition economies, addressing a gap left by the more resource-intensive INTOSAI Performance Measurement Framework (PMF). Design/methodology/approach — The study employs a sequential explanatory mixed-methods design (Saunders et al., 2019). The ICRC index was constructed through a four-dimensional structure (Legal Conformity, Institutional Conformity, Operational Conformity, Reform Capability) comprising 17 assessment aspects, with weights derived through expert consensus (Delphi method, n=15). Reliability was tested using Cronbach's alpha. The framework was applied to the Accounts Chamber of the Republic of Uzbekistan as a case study. Findings — The ICRC index demonstrated acceptable internal consistency (α = 0.87). The Uzbek SAI achieved an overall ICRC score of 2.94/5.00 ("upper-medium" compliance). Dimensional decomposition revealed significant gaps in institutional independence (IC = 1.50) and ethics framework adoption (1.5/5), while reform capability (RC = 3.50) showed promise. The framework successfully identified prioritization pathways consistent with recent reform decrees (PF-100, 2024; PF-252, 2025). Research limitations/implications — The relatively small expert sample (n=15) constrains statistical generalization. Cross-validation with other Central Asian SAIs (Kazakhstan, Kyrgyzstan, Tajikistan) is recommended as a future research direction. Originality/value — This study contributes a parsimonious yet comprehensive assessment tool that fills a methodological gap for emerging SAIs. The introduction of "Reform Capability" as an explicit dimension distinguishes the ICRC from existing static frameworks.