This study examines how age misreporting typically affects estimates of mortality at older ages. We investigate the effects of three patterns of age misreporting - net age overstatement, net age understatement, and symmetric age misreporting - on mortality estimates at ages 40 and above. We consider five methods to estimate mortality: conventional estimates derived from vital statistics and censuses; longitudinal studies where age is identified at baseline; variable-r procedures based on age distributions of the population; variable-r procedures based on age distributions of deaths; and extinct generation methods. For each of the age misreporting patterns and each of the methods of mortality estimation, we find that age misstatement biases mortality estimates downwards at the oldest ages.