OBJECTIVES: Tofacitinib is an oral small molecule Janus kinase inhibitor for the treatment of moderate to severe rheumatoid arthritis (RA) in adults who have an inadequate response to methotrexate. The aim of this work is to estimate the budget impact of the inclusion of tofacitinib in the public list of reimbursement in Colombia. METHODS: A model was built with a time horizon of three years. The comparators were:abatacept, adalimumab, certolizumab, etanercept, infliximab, golimumab, rituximab, tocilizumab, and tofacitinib. The perspective was of the Colombian health system including only direct costs: drug costs and administration costs. All currency units were in USD $ (1 USD$ = COP 1,971). A 5% discount rate was used. The number of expected cases was calculated from the single national register of members of the Colombian health system (BDUA). Additionally a prevalence of 0.52% was used and we assumed that 30% of patients were refractory to initial treatment with non-biologic DMARDs. The costs of drugs were used current price regulation and the official database of purchase and sale of drugs (SISMED). The market share was estimated based on SISMED and the projected demand validated by expert physician. RESULTS: As the use of tofacitinib is increased from 0.9% (current scenario) to 15.3% (projected for three years) total spending is reduced in USD $ 80,345,510 equivalent to 5% of total expenditure of this pathology in Colombia. CONCLUSIONS: The use of tofacitinib in patients who have an inadequate response to methotrexate, decreases total costs of care for the health system in Colombia.