Use of recommended preventive care services in the United States is not universal and varies considerably by socio-economic status. We examine whether widespread eligibility for Medicare at age 65 narrows disparate preventive service use by race and ethnicity. Using data across 12 cycles of the Household Component of the Medical Expenditure Panel Survey (2005-2016), we employ a regression discontinuity design to assess changes in the use of preventive services. Our sample included: 8847 Hispanic respondents, 9908 non-Hispanic Black respondents, and 29,527 non-Hispanic White respondents. We examined six preventive services: routine check-ups, blood cholesterol screenings, receipt of the influenza vaccine, blood pressure screenings, mammograms, and colorectal cancer screenings. For non-Hispanic Black adults, we found that preventive service use increased after age 65 across a range of measures including a 4.8 percentage-point (95% confidence interval (CI)1.4, 8.2) increase in blood cholesterol screening, and a 9.1 percentage-point (95% CI 2.1, 15.9) increase in mammograms for Black women. For all four preventive health measures that were lower for Hispanic adults compared with non-Hispanic White adults prior to age 65, service use was indistinguishable (p > 0.10) between these groups after reaching the Medicare eligibility age. Medicare eligibility appeared to reduce most racial and ethnic disparities in preventive service use.