OBJECTIVE: To identify standardized mortality rate (SMR) differences among adults with varying access to medical services in Mexico over a decade. STUDY DESIGN: Retrospective longitudinal study. METHODS: We compared SMR between insured and uninsured adults with epilepsy in Mexico (Ethics Committee number: CE/FESI/042023/1612). Mortality data from 2005 to 2006 and 2015-2016 were obtained from the National Institute of Statistics and Geography (INEGI). Crude death rates (CDR) per 100,000 person-years were calculated, and SMRs with 95 % confidence intervals (CI) adjusted for age and gender were estimated using Stata V.15. RESULTS: In 2005-2006, there were 658 epilepsy-related deaths (CDR = 0.91 per 100,000 person-years). In 2015-2016, there were 1916 deaths (CDR = 1.22 per 100,000 person-years). The 2005-2006 age-adjusted mortality rate was higher in the insured [0.84 (95 % CI 0.80-0.96)] than the uninsured [0.16 (95 % CI 0.10-0.29)]. In 2015-2016, the uninsured mortality rate was 1.55 (95 % CI 0.76-2.11) versus 1.10 (95 % CI 0.62-1.99) for the insured. Mortality rates increased with age, especially in the uninsured. CONCLUSIONS: Mortality due to epilepsy was higher among the uninsured. Rates were higher in men than women. In Mexico, SMR increases after age 50, with the elderly consistently showing higher SMR in both insured and uninsured groups. Our findings show a substantially changed mortality of epilepsy between insured and no insured population. Reasons for these inequalities in mortality rates are apparent but also are likely to be multifactorial.