To analyze the association of changes in social security (SS) continuity and mortality, using the Mexican Health and Aging Study (MHAS) in people aged 60 years and more. Retrospective cohort. We analyzed the SS continuity condition -classified as stable, unstable with SS, unstable without SS, and without SS- and its relation with mortality; a probit regression model was utilized to obtain marginal effects, taking into consideration covariates related to mortality. Unstable continuity with and without SS and multimorbidity (two or more diseases) increased the probability of dying by 52.9% (p = 0.000, 95%CI: 0.508,0.551), 50.3% (p = 0.000, 95%CI: 0.474,0.531) and 13.3% (p = 0.000, 95%CI: 0.108,0.159), respectively. Meanwhile, being woman, at least one year of formal education, and marriage reduced it in 8.8% (p = 0.000, 95%CI: -0.106,-0.071), 7% (p = 0.000, 95%CI: -0.091,-0.050) and 7.8% (p = 0.000, 95%CI: -0.096,-0.061), respectively. Belonging to SS was associated with higher mortality, compared to other social health determinants, like education.