OBJECTIVES: Dipeptidyl peptidase-4 enzyme inhibitors (DPP-4is) are a class of oral antidiabetic medications approved to lower blood glucose in patients with type 2 diabetes (T2DM). This analysis compared adherence and persistence over 1-year and 2-year periods among T2DM patients initiating saxagliptin or sitagliptin, two DPP-4is.  METHODS: Adults with T2DM in the MarketScan® US claims database who initiated saxagliptin or sitagliptin (index drug) between 1/1/2009-1/31/2012 with no use of DPP-4is in the previous year were included. 1 year continuous enrollment pre-initiation and 1 year post-initiation were required. A sub-group of patients had 2 years of post-initiation enrollment. Adherence was defined as proportion of days covered (adherent if ≥0.80), and persistence was defined as time to discontinuation (end of days’ supply of index drug prior to gap of 60 days). Logistic regression and proportional hazards regression models adjusted for demographic, clinical, and prescription characteristics.  RESULTS: