OBJECTIVES: To evaluate the economic impact of using saxagliptin/metformin XR FDC versus sulfonylurea (SU) plus metformin (MET) in Colombia, in people with type 2 diabetes (T2DM) who do not achieve treatment goal only with MET. METHODS: A discrete event simulation model (Cardiff diabetes model) based on UKPDS 68 was used to simulate disease progression and to estimate the economic and health treatment consequences in people with T2DM. Epidemiologic and clinical efficacy parameters were obtained from the literature. Cost of medication was obtained from country level drug prices, SISMED and Farmaprecios; cost of macro and microvascular events were based on POS tariffs, SOAT Manual and consultation with a local expert. A 20-year time horizon was assumed. Costs and health outcomes were discounted at 3% annually. Deterministic and probabilistic sensitivity analysis were also performed. RESULTS: The group treated with saxagliptin/metformin XR had fewer non-fatal events and episodes of hypoglycemia than the SU plus MET treated group. The model also predicted a lower number of fatal macrovascular events for the saxagliptin/metformin XR group (159 vs. vs. US$ 14,735,176). Treatment with saxagliptin/metformin XR resulted in a greater number of quality-adjusted life years (QALYs) and life-years gained (LYG) than the SU combination (10,203 vs.