Purpose <p>To identify key risk factors associated with the progression from prediabetes to type 2 diabetes in a majority-minority county in the United States and evaluate their relative contributions.</p> Methods <p>We conducted a retrospective cohort study using the deidentified EHR from the University of California, Irvine Health (2013–2023). Adults with prediabetes (confirmed by ICD codes and HbA1c values) were included, and those with diabetes of any form at baseline or with missing data were excluded. Baseline demographics and clinical factors were compared among those who progressed to T2D (converters) to those who did not (non-converters). Ordinal logistic regression and Cox proportional hazards models were used to assess predictors of conversion timing and risk.</p> Results <p>A total of 2648 adults had confirmed prediabetes, of which 510 (19.3%) developed T2D. Among converters, 81.6% progressed within 5 years of the initial prediabetes diagnosis. The two groups were similar at baseline, except converters had higher obesity rates and were more likely to have Hispanic/Latino ethnicity (<i>p</i> &lt; 0.001). Elevated baseline HbA1c was a strong independent predictor of earlier conversion to T2D (OR 0.41 per 1% increase, <i>p</i> &lt; 0.001). Baseline triglycerides provided a modest additional effect (<i>p</i> = 0.047). Hispanic/Latino ethnicity was associated with a significantly higher risk of progression to T2D (adjusted HR 1.25, 95% CI 1.03–1.49, <i>p</i> = 0.021).</p> Conclusions <p>Elevated HbA1c and triglycerides at baseline were associated with early conversion to T2D. This study underscores the need for early, targeted intervention in individuals with high-risk ethnic and clinical profiles to stop T2D.</p>