We successfully implemented the American Diabetes Association's (ADA) Diabetes INSIDE (INspiring System Improvement with Data-Driven Excellence) quality improvement (QI) program at a university hospital and safety-net health system (Tulane and Parkland), focused on system-wide improvement in poorly controlled type 2 diabetes (HbA1c >8.0% [64 mmol/mol]). In this study, we estimated the 5-year risk reduction in complications and mortality associated with the QI program.The QI implementation period was 1 year, followed by the postintervention period of 6 months to evaluate the impact of QI on clinical measures. We measured the differences between the baseline and postintervention clinical outcomes in 2,429 individuals with HbA1c >8% (64 mmol/mol) at baseline and used the Building, Relating, Assessing, and Validating Outcomes (BRAVO) diabetes model to project the 5-year risk reduction of diabetes-related complications under the assumption that intervention benefits persist over time. An alternative assumption that intervention benefits diminish by 30% every year was also tested.The QI program was associated with reductions in HbA1c (-0.84%) and LDL cholesterol (LDL-C) (-5.94 mg/dL) among individuals with HbA1c level >8.0% (64 mmol/mol), with greater reduction in HbA1c (-1.67%) and LDL-C (-6.81 mg/dL) among those with HbA1c level >9.5% at baseline (all P < 0.05). The implementation of the Diabetes INSIDE QI program was associated with 5-year risk reductions in major adverse cardiovascular events (MACE) (relative risk [RR] 0.78 [95% CI 0.75-0.81]) and all-cause mortality (RR 0.83 [95% CI 0.82-0.85]) among individuals with baseline HbA1c level >8.0% (64 mmol/mol), MACE (RR 0.60 [95% CI 0.56-0.65]), and all-cause mortality (RR 0.61 [95% CI 0.59-0.64]) among individuals with baseline HbA1c level >9.5% (80 mmol/mol). Sensitivity analysis also identified a substantially lower risk of diabetes-related complications and mortality associated with the QI program.Our modeling results suggest that the ADA's Diabetes INSIDE QI program would benefit the patients and population by substantially reducing the 5-year risk of complications and mortality in individuals with diabetes.