A common way of describing the course of educational attainment over time, among demographers, is in terms of cohort succession. This description rests on the premise that, for much of the life course, level of education is a relatively fixed characteristic. In recent years, some doubt has been shed on this model as a result of possible changes over time, a shift in focus to college completion, and increasing interest in gender differences in education. This paper examines the cohort succession model by taking advantage of a large collection of data from the Current Population Survey (CPS), from 1967 to 2015. It examines factors that might influence the cohort changes in college completion with age, as recorded in the CPS. These factors include continuing education, differential mortality, and immigration.