This study aims to identify the barriers to Enterprise Risk Management (ERM) implementation, examine the Critical Success Factors influencing the Risk Maturity Index (RMI), and formulate strategies to enhance risk management maturity at PT XY as a representative case study of an Indonesian state-owned construction enterprise. A quantitative approach was employed using the Partial Least Squares Structural Equation Modeling (PLS-SEM) method with SmartPLS software. Data were collected from 80 respondents selected through purposive sampling. Instrument validity was assessed using the Content Validity Index (CVI) involving six experts, resulting in an S-CVI/Ave value of 0.875, indicating that the research instrument was valid and suitable for use. The findings indicate that ERM implementation barriers have a significant negative effect on both ERM Strategy Implementation and the Risk Maturity Index, whereas Critical Success Factors have a significant positive effect on both variables. Furthermore, ERM Strategy Implementation has a significant positive effect on the Risk Maturity Index and serves as a partial mediating variable in the relationship between ERM implementation barriers, Critical Success Factors, and the Risk Maturity Index. The proposed model demonstrates strong predictive capability, with R² values of 0.737 for ERM Strategy Implementation and 0.886 for the Risk Maturity Index. Based on these empirical findings, four key improvement strategies were developed through a Strength–Weakness Analysis, validated by experts using the Content Validity Index (CVI), and translated into an implementation roadmap. This study contributes to the literature by proposing an integrated model that combines ERM implementation barriers, Critical Success Factors, and ERM Strategy Implementation to formulate evidence-based strategies for improving the Risk Maturity Index.