Introduction: Even though several landmark statin trials have demonstrated the beneficial effects of statin therapy in both primary and secondary prevention of cardiovascular disease, several studies have suggested that statins are associated with a moderate increase in risk of new-onset diabetes. These observations prompted the US FDA to revise statin labels to include a warning of an increased risk of incident diabetes mellitus as a result of increases in glycosylated hemoglobin (HbA1c) and fasting plasma glucose. However, few studies have used US-based data to investigate this statin-associated increased risk of diabetes. Objective: The primary objective of our study was to examine whether the use of statins increases the risk of incident diabetes mellitus using data from the Thomson Reuters MarketScan® Commercial Claims and Encounters Database. Method: This study was a retrospective cohort analysis utilizing data for the period 2003–2004. The study population included new statin users aged 20–63 years at index who did not have a history of diabetes. Results: The proportion (3.4 %) of statin users (N = 53,212) who had incident diabetes was higher than the proportion (1.2 %) of non-statin users (N = 53,212) who had incident diabetes. Compared with no statin use and controlling for demographic and clinical covariates, statin use was significantly associated with increased risk of incident diabetes (hazard ratio 2.01; 99 % confidence interval 1.74–2.33; p < 0.0001). In addition, risk of diabetes was highest among users of lovastatin, atorvastatin, simvastatin, and fluvastatin. Diabetes risk was lowest among pravastatin and rosuvastatin users. Discussion: Because the potential for diabetogenicity differs among different statin types, healthcare professionals should individualize statin therapy by identifying patients who would benefit more from less diabetogenic statin types.