With data on occupational task content from O*NET and ORS and survey data from the American Community Survey (ACS) and 1979 National Longitudinal Survey of Youth (NLSY79), we document how the physical, cognitive, routine, and social characteristics of work in the United States have evolved since the early 2000s; examine how the task content of work changes of the lifecycle; and estimate the effects of changing task content on work outcomes. We find that the intensity of routine manual and routine cognitive tasks has risen, since early in 21st century. Workers nearing retirement have experienced declining rates of nonroutine tasks, while routine tasks have risen over time. We find significant racial/ethnic and gender differences in task content over the lifecycle. White and Asian workers tend to work in occupations high in nonroutine cognitive tasks. Hispanic and Black workers, especially men, work in the most physically demanding jobs over their entire working lives. we find the largest earnings gains are associated with higher nonroutine cognitive analytical, nonroutine cognitive interpersonal, and social skill tasks. Workers who worked in an occupation in 2004 with high cognitive analytical task intensity were out of the labor force less, while those employed in an occupation with high nonroutine manual physical tasks were out of the labor force more.