BackgroundAn emerging body of evidence suggests that autistic people are at greater risk for mortality than non-autistic people. Yet, relatively little is known about mortality rates among autistic people during older adulthood (i.e., age 65 or older). MethodsWe examined 5-year mortality among a national US sample of Medicare-enrolled autistic (n = 3308) and non-autistic (n = 33,080) adults aged 65 or older. ResultsAutistic older adults had 2.87 times greater rate of mortality (95 % CI = 2.61–3.07) than non-autistic older adults. Among decedents (39.6 % of autistic and 15.1 % of non-autistic older adults), the median age of death was 72 years (IQR = 69–78) for autistic and 75 years (IQR=70–83) for non-autistic older adults. Among autistic older adults, those with intellectual disability had 1.57 times greater rate of mortality (95 % CI = 1.41–1.76) than those without, and males had 1.27 times greater rate of mortality (95 % CI = 1.12–1.43) than females. ConclusionsMany trends regarding mortality observed in younger samples of autistic people were also observed in our study. However, we found only a three-year difference in median age at death between autistic and non-autistic decedents, which is a much smaller disparity than reported in some other studies. This potentially suggests that when autistic people live to the age of 65, they may live to a more similar age as non-autistic peers.