Recent research has proposed that shifting education distributions across cohorts are influencing estimates of educational gradients in mortality. We use data from the United States and Finland covering four decades to explore this assertion. We base our analysis around our new finding: a negative logarithmic relationship between relative education and relative mortality. This relationship holds across multiple age groups, both sexes, two very different countries, and time periods spanning four decades. The inequality parameters from this model indicate increasing relative mortality differentials over time. We use these findings to develop a method that allows us to compute life expectancy for any given segment of the education distribution (e.g., education quintiles). We apply this method to Finnish and American data to compute life expectancy gradients that are adjusted for changes in the education distribution. In Finland, these distribution-adjusted education differentials in life expectancy between the top and bottom education quintiles have increased by two years for men, and remained stable for women between 1971 and 2010. Similar distribution-adjusted estimates for the U.S. suggest that educational disparities in life expectancy increased by 3.3 years for non-Hispanic white men and 3.0 years for non-Hispanic white women between the 1980s and 2000s. For men and women, respectively, these differentials between the top and bottom education quintiles are smaller than the differentials between the top and bottom education categories by 18% and 39% in the U.S. and by 39% and 100% in Finland. Had the relative inequality parameters of mortality governing the Finnish and U.S. populations remained constant at their earliest period values, the difference in life expectancy between the top and bottom education quintiles would – because of overall mortality reductions – have declined moderately. The findings suggest that educational expansion may bias estimates of trends in educational differences in life expectancy upwards.