OBJECTIVES: Polish children and adolescents suffering from severe ulcerative colitis (UC) refractory to conventional therapies have limited access to innovative therapy recommended by clinical guideline. Existing healthcare treatment programme (HTP) for adults financed by the National Health Fund (NHF) should be extended for population below 18 years of age, which is the only chance to avoid or delay debilitating colectomy procedure. The aim of this analysis was to estimate financial consequences of biosimilar infliximab (bioINF) reimbursement for pediatric population within the HTP on the budget of NHF in Poland. METHODS:  Budget Impact Analysis (BIA) was performed for 2 years’ time horizon (2016-2017). Target population qualified to the HTP were children and adolescents (age 6-17 years) with severe UC who had an inadequate response, or are intolerant, or have medical contraindications to therapy including corticosteroids and 5-aminosalicylates or thiopurines (6-mercaptopurine or azathioprine). Two scenarios were compared: present, without bioINF reimbursement and new, with reimbursement of bioINF as part of HTP. Only direct medical costs were included: costs of drugs and their administration, cost of hospitalization, colectomy and monitoring. The calculations were performed in the Microsoft Office Excel spreadsheet. RESULTS: NHF annual expenditures related to introduction of bioINF reimbursement would increase by €474,071 in 2016 and €474,199 in 2017 comparing with the present scenario (€1 = PLN 4.39). Number of newly treated patients would be 136 in 2016 and 136 in 2017. CONCLUSIONS: Financing infliximab by NHF will be connected with additional expenditure, however infliximab is the only rescue treatment before colectomy recommended by clinical guidelines. Furthermore significantly lower price of bioINF in comparison with reference infliximab gives possibility to treat more patients within the same budget.