OBJECTIVES : Recent studies reported that seeing an endocrinologist is associated with better compliance with guidelines on diabetes management. This study aims at investigating the socioeconomic determinants of endocrinologist visits among a French population of diabetics. METHODS: We used claim data collected for 66,508 affiliates of a French social security provider (MGEN). Patients were aged over 18 and treated for diabetes (types I and II). We ran logistic regressions to explore which factors were associated with the probability of consulting an endocrinologist. We controlled for patients’ socioeconomic characteristics (sex, age, income, marital status, activity status), type of treatment, medical care and health status. We also controlled for macro-level variables, such as the cost for a visit, the distance to the office and the medical density.  RESULTS: Women, married patients, and those working are more likely to consult an endocrinologist (p<0.001). Age has a non-linear association with the probability of seeing an endocrinologist: rates of specialist visits are the largest under the age of 25 (p<0.05). In addition, people treated with insulin and those with another endocrine disorder are more likely to see a specialist (p<0.001). In contrast, the newly diagnosed and patients followed by a general practitioner (GP) present lower probabilities of specialist visits (p<0.001). Moreover, the probability of specialist visit rises when the density of endocrinologists is large in the patients’ neighbourhood, while it decreases with the distance (in kilometres) from the patients’ house to the endocrinologist’s office. Finally, the chances of seeing a specialist increase with income and decrease as the cost for a visit rises.  CONCLUSIONS: Our results are consistent with previous literature showing evidence of the existence of a substitution effect between GPs and specialists in diabetes care. We show that financial barriers exist even in a population of patients receiving national health insurance coverage.