OBJECTIVES:  To develop a cost minimization analysis in the switch of infliximab to it biosimilar, in the treatment of rheumatoid arthritis (RA) from the perspective of Brazilian private health system (BPHS). METHODS:  A cost minimization analysis model was developed to measure the impact of treatment switch from Infliximab to its biosimilars. The analysis considered the perspective of the BPHS, and has included only direct costs of medicines (as regulated by the local Ministry of Health), in a cohort of