We provide a novel decomposition of changing gaps in life expectancy between rich and poor into differential changes in age-specific mortality rates and differences in “survivability”. Declining age-specific mortality rates increases life expectancy, but the gain is small if the likelihood of living to this age is small (ex-ante survivability) or if the expected remaining lifetime is short (ex-post survivability). Lower survivability of the poor explains half of the recent rise in inequality in the US and the entire rise in Denmark. Declines in cardiovascular mortality benefited rich and poor, but inequality increased because of differences in lifestyle-related survivability.