Education was added to the U.S. Standard Certificate of Death in 1989. The current study uses Michigan's 1989-1991 death certificates, together with the 1990 Census, to evaluate the quality of data on education from death certificates and to examine educational differences in mortality rates. With log-rates modeling, we systematically analyze the variability in educational differences in mortality by race and sex across the adult life cycle. The relative differences in mortality rates between educational levels decline with age at the same pace for all sex and race categories. Women gain a slightly greater reduction in mortality than men by reaching the secondary-education level, but a modestly smaller reduction by advancing beyond it. Blacks show a reduction in predicted mortality rates comparable to whites' by moving from the secondary to the postsecondary level of education but experience less reduction than whites by moving from the primary to the secondary level. Thus, the secular decline in mortality rates that generally accompanies historical improvements in education might actually be associated with an increase in the relative differences between blacks' and whites' mortality. We discuss limitations of the data and directions for future research.