In France, in the early 2000s, legislators ordered that the National Health Insurance regime develop an inter-regime information system (SNIIR-AM) aimed at better understanding and evaluating beneficiaries' health care consumption and associated expenditures. In 2009, it contained data from the general health insurance regime that covers 86% of the French population; approximately 53 million people. Data are only available for a period of two years plus the current year. In addition, a permanent sample of health insurance beneficiaries (EGB) was created from the SNIIR-AM database. This is a permanent, representative cross-sectional sample of the population covered by National Health Insurance which, since 2004, monitors beneficiaries' health care consumption over a period of 20 years. It contains anonymous sociodemographic and medical characteristics and records of health care reimbursements. It was created using a systematic sampling method (1/97) on the two-digit control key of beneficiaries' national identification number and includes both current year reimbursement recipients and non-recipients. In 2009, it grouped together almost 500,000 beneficiaries covered by the National Health Insurance Fund for Salaried Workers; 77% of the population residing in France excluding public service employees and students. The EGB is used to conduct longitudinal studies as it permits tracing back patients' care paths and use of care in both hospital and office-based care environments and to calculate individual expenditures. It also permits the study of certain relatively frequent diseases characterised by a 100% reimbursement rate for certain chronic diseases and the reimbursement of tracer drugs. Eventually, the SNIIR-AM will include beneficiaries covered by all the different Health Insurance regimes in France.