Using HRS data matched with Social Security administrative data, we document large gender differences in disability insurance programs admission rates and type I error rates. In particular, women who apply for DI/SSI are 13 percentage point less likely to be awarded benefits than men, controlling for health, occupation and a host of demographic characteristics. Moreover, women who self-report to be disabled are 20 percentage points more likely to be rejected than observationally similar men. We investigate whether these gender differences can be explained by heterogeneity in underlying unobserved health, differences in disability perceptions, higher noise-to-signal ratios, or SSA evaluators’ assessment bias. We find little support for the first three explanations, and some indirect support for the latter.