THE CONTEXT OF ATTRIBUTION: The invalidity insurance is aimed at providing financial assistance to working people aged under 60 years of age and who have lost more than 2/3 of their capacity to work or earn a living, following a non-occupational disease or accident or due to "premature ageing of the organism". THREE CATEGORIES OF INVALIDITY: Depending on the extent of the reduction in earning capacity, distinction is made between invalid persons capable of earning a living, those totally incapable of working and persons incapable of working but who also are obliged to rely on help of a third person to perform ordinary daily functions. THE ATTRIBUTION CRITERIA: The evaluation is made by the counselling physician of the social security system, who must take into account not only the medical but also professional and social criteria. The invalidity can be revised. Since the pension is attributed temporarily, it can be suspended or withdrawn. ASSISTANCE IN THE CASE OF REFUSAL: There are 3 routes of assistance, depending on whether the refusal is administrative, medical due to a non-stabilised affection, or medical due to a stabilised affection with incapacity inferior to 2/3.