OBJECTIVES: The BI.2IM Project started in 2010 to improve costs control and register resource utilization of several Brazilian HMOs based on an already established (2007) administrative database. The project has evolved in 2011 for another utilization related to payment for performance (P4P) and evaluation of standard of resource utilization (in-hospital and medical office based data), allowing to follow identified patients over prolonged periods of time and to study the quantity and cost of health care services provided. Therefore, this 5 million lives database (BI.2iM) probabily allows retrospective health care resource utilization studies based upon the registered data and their related costs. The aim of this study is to verify if BI.2iM database is statistically comparable with the total Brazilian Private Healthcare population in terms of regional distribuition, gender and age. METHODS: The sample quantity of patients was statistically compared with the total private market population in terms of regional distribution and gender. Other available information was accessed and compared too. RESULTS: The sample compares well to the national private market population (sample error of 0,044%) as well as in terms of regional distribution. The BI.2iM database can be searched by ICD10 code, Brazilian codes for procedures and tests and allows follow up of the patient’s treatment. CONCLUSIONS: The BI.2iM sample constitutes a well-characterized supplementary health study population statistically comparable to the national private market population. Its results extrapolated to the total supplementary health care together with the public health care database (DATASUS) may enable evaluation the total Brazilian Healthcare market.