Objective To examine the impact of Seguro Popular (Mexican social health insurance for the poor; SP) on diabetes and hypertension care, intermediate process indicators for older adults (>50 years): pharmacological treatment, blood glucose tests, the use of complementary and alternative medicine (CAM), and adherence to their nutrition and exercise program. (CAM was defined as products or practices that were not part of the medical standard of care.) Data Sources/Study Setting Repeated cross‐sectional surveys from Encuesta Nacional de Salud y Nutrición (Mexican Health and Nutrition Survey, ENSANUT), a nationally representative health and nutrition survey sampling N = 45,294 older adults in 2000, N = 45,241 older adults in 2005–2006, and N = 46,277 older adults in 2011‐2012. Study Design Fixed‐effects instrumental variable (FE‐IV) repeated cross‐sectional at the individual level with municipality fixed‐effects estimation was performed. Principal Findings We found a marginally significant effect of SP on the use of insulin and oral agents (40 percentage points). Contrary to that expected, no other significant differences were found for diabetes or hypertension treatment and care indicators. Conclusions Social health insurance for the poor improved some but not all health care process indicators among diabetic and hypertensive older people in Mexico.