Rural-urban mortality differences are a topic of considerable relevance for population health in many high-income societies. Current developments seem to particularly compromise the situation in many rural areas, where countries frequently struggle to maintain adequate health services for rapidly ageing populations. However, comparisons of mortality levels across the rural-urban scale are often biased by the fact that rural and urban areas differ in their overall mortality levels. To overcome this limitation, we compare urban-rural old-age mortality differences in Germany and England & Wales (NUTS-3-level) only across districts with similar life expectancy levels at age 60. We find an urban-rural mortality crossover in all life expectancy groupings. Most urbanized regions report the highest death rates at ages below the crossover (ages < 75-79), and the lowest death rates at ages above the crossover (ages 80+). This mortality crossover suggests systematic survival disadvantages that depend on age and the degree of urbanization.