In the late 2000s, the rate of employment for people with disabilities in France was 46%, compared to 72% for people without disabilities. While we are able to assess the cost of compensation in terms of health insurance for temporary incapacity to work due to illness (€6.7 billion or 3.7% of health spending in 2012), we still know little about the effects of sick leave on career paths. This study analyses the impact of sick leave - which constitutes a measure of temporary working incapacity - on the momentum of career paths. It draws on administrative data on careers and health costs of employees affiliated to the General Scheme (Hygeia panel 2005-2008). A typology has been applied to characterise the transitions between five states (employment without leave, employment with few sick leave periods, employment with long sick leave periods, unemployment and inactivity). Using a dynamic multinomial model with fixed effects allows estimation of the impact of sick leave periods on unemployment and inactivity from one year to the next by distinguishing state dependency from unobserved heterogeneity. We observe career paths which deteriorate more in the long term (resulting particularly in unemployment and inactivity) among sick leave takers, particularly where they result from long periods of illness. This effect is similar for men and women; the higher risk of inactivity after long sick leave periods among women is mainly explained by unobserved heterogeneity. While short sick leave periods can a priori be interpreted as a marker of job security, once unobserved heterogeneity is taken into consideration, they are also a risk factor for employees when their cumulative length exceeds 30 days. Furthermore, employees seem to incorporate these penalty risks by limiting their recourse to sick leave following periods of unemployment or inactivity.