OBJECTIVES: To evaluate the changes in the cost of HCV therapy after boceprevir addition to standard therapy. The analysis is made from the third party payer perspective for one year time horizon. METHODS: Budget impact model was used combining the HCV epidemiology data, and differences in the boceprevir efficacy in naive and experienced patients with relapse. The cost of pharmacotherapy was calculated for treatment naive (n=191) and experienced patients (n=98) alone, as well as for achieving sustained virusologycal response. Standard therapy cost alone and standard therapy plus boceprevir was compared to derive the budget impact. RESULTS: Pharmacotherapy cost differs among subgroups of patients with heavier burden for the experienced cirrhotic patients (36,000 Euro). Increase in the cost of pharmacotherapy in treatment naive group is twice after boceprevir addition but efficacy is three times higher. Addition of boceprevir to treatment naive early responder patients led to the overall decrease in their cost of therapy to 29,000 Euro. The decrease in mean pharmacotherapy cost of standard regime was also observed after boceprevir addition thus influencing positively the overall treatment cost. For treatment experienced patients the efficacy is lower but still it is twice higher than that of the standard therapy. Achievement of sustained virusologycal response in experienced group saves approximately 7,500 Euro per patient in comparison with standard therapy.  CONCLUSIONS: Addition of boceprevir to standard HCV therapy led to the overall decrease in therapy cost mostly evident in treatment experienced patients.