OBJECTIVES: To estimate the budget impact of Saxagliptin introduction as a treatment option for patients with type 2 diabetes mellitus (DM2) compared to the present situation. METHODS: An MS Excel-based budget impact model assuming coverage for one million people. The time horizon was three years and the analysis perspective was that of the public health care system in Chile. Pharmaceutical expenses of antidiabetic agents were analyzed, excluding other medical costs. The cost of antidiabetic agents was based upon list prices adjusted to co-payments, expressed in 2009 United States dollars; the Saxagliptin price was considered to be equal to the sitagliptin price. The market share of the different drugs was based upon market studies and data provided by Bristol Myers Squibb. The budget impact is reported in terms of annual budget impact, per member per month (PMPM). The cost of pioglitazone and rosiglitazone related cardiovascular events, as well as that of sulphonylureas related hypoglycemia events were expressed as rates of occurrence per patient per year and cost per occurrence. RESULTS: The estimated net budget impact for the introduction of Saxagliptin was US$ 70,723, US$ 162,885 and US$ 251,574 for the first, second and third year respectively; the cumulative net budget impact was US$ 485,181. PMPM was US$ 0.0059, US$ 0.0136 and US$ 0.0209 each year, respectively. The cumulative impact in the total annual budget for antidiabetics represented an increase of 4.22%. CONCLUSIONS: The budget impact of adding Saxagliptin in a population of one million people to the public health care system in Chile is minimal in patients with DM2. The rise in pharmaceutical expenses derived from introducing Saxagliptin into the formulary is balanced by savings in terms of reduction of adverse events related to thiazolidinediones and sulfonylureas, as well of lowering of insulin requirements in an extended time horizon.