Objectives: We examine survey reporting of Medicare coverage of the older population by evaluating discordance between survey responses and administrative records. Method: We link data from the 2014 Current Population Survey Annual Social and Economic Supplement (CPS ASEC) and 2014 Medicare Enrollment Database to evaluate the extent to which individuals misreport Medicare coverage in the CPS ASEC. Using regression analyses, we assess factors associated with misreporting. Results: We find the CPS ASEC undercounts the population aged 65 years and older with Medicare by 4.5%. Misreporting of Medicare coverage is associated with citizenship status, immigration year of entry, employment, coverage of other household members, and imputation of Medicare responses. Adjusting for misreporting, Medicare coverage among older individuals increases from 93.4% to 95.6%. Discussion: The CPS ASEC underestimates Medicare coverage for the older population. Administrative records may be useful to evaluate and improve survey imputation of Medicare coverage when missing.