Objectives: The health status of the population in the overseas departments (DOM) is poorer than that of the population in metropolitan France. Furthermore, the proportion of recipients of the supplementary universal health coverage (CMU-C), granted to low-income individuals, is higher in the DOMs than in mainland France, even though studies have shown that in mainland France, these recipients are in poorer health than the rest of the population. Is this poorer health among CMU-C beneficiaries also a reality in the DOMs, and to what extent does it explain the poorer health of residents compared to those in metropolitan France? Methods: The National Inter-Regime Health Insurance Information System (Sniiram) was used to identify, for the year 2012, the conditions covered using algorithms, as well as the mortality rates of insured individuals in the general scheme under the age of 60—the age group eligible for CMU-C. Age- and sex-standardized relative risks between CMU-C beneficiaries and non-beneficiaries were calculated in each French overseas department (DOM). The proportion of health status differences between the DOMs and mainland France explained by CMU-C coverage was estimated. Results: the study populations were 244,896 in Guadeloupe, 237,320 in Martinique, 112,423 in French Guiana, 571,324 in Réunion, and 36 million in metropolitan France. In these overseas departments, the proportions of CMU-C beneficiaries were 35%, 35%, 54%, and 50%, respectively, versus 11% in mainland France. In each overseas department, CMU-C beneficiaries had higher mortality rates (RR: 1.6; 1.9; 2.2; 1.7, respectively) and were more frequently diagnosed with conditions covered by the program as recorded in the Sniiram database. Differences in health status between the French overseas departments and mainland France were rarely fully explained by the overrepresentation of CMU-C beneficiaries in the overseas departments. Conclusion: in each overseas department, with comparable age and sex structures, CMU-C beneficiaries under 60 years of age have poorer health than the rest of the population, according to healthcare utilization data. Although the proportion of CMU-C beneficiaries is higher in the French overseas departments than in mainland France, this overrepresentation alone does not explain the differences in health status between the French overseas departments and mainland France.