Administrative data from the National Health Data System (SNDS) are increasingly used for epidemiological surveillance of chronic diseases. In the context of the population ageing being able to anticipate the future burden of dependency is a central public health issus. SNDS data represent one possible approch to develop an effective monitoring system for loss of autonomy. Given the continuum between good health and the state of dependency, the objective of this study is to develop an indicator able to categorize individuals according to their level of frailty (robust, pre-frail, frail, dependent). The use of data from the 2012 Health and Social Protection Survey, in which the information regarding frailty and dependency are well defined, linked to the SNDS data, will allow to develop a frailty indicator based on data available in our French medico-administrative databases. Thir indicator will open important perspectives in the fileds of elderly health’ surveillance, reasearch and prevention.