Based on a method to estimate undergraduate enrollments using age and residency information, undergraduate projections to 1990 for Connecticut colleges and universities are presented. Implications of the projections for competition among institutions and postbaccalaureate enrollments are also addressed. The projections show little overall decline in total undergraduate headcount enrollment to 1985. If students of the same age and from the same residence areas were to continue to attend the same types of institutions at the same rates as they did in fall 1980, full-time equivalent (FTE) enrollment would fall about 3 percent by 1985. By 1990, the headcount decline would be 6 percent, with an FTE decline of about 11 percent. In addition to headcount and FTE enrollment projections, separate estimates were calculated for full-time and part-time students. No specific projections were made for postbaccalaureate education; however, changes in enrollment at this level will modify overall enrollment levels in institutions offering graduate education. In 1980, 31 percent of all undergraduates in Connecticut institutions were over 24 years old. It appears that adult learners are currently participating at rates that can be expected to compensate substantially for the declining numbers of younger students. The 25- to 34-year-old age group will increase numerically during the 1980s as the population peak moves along, and by 1990, 40 percent of undergraduate students in Connecticut institutions of higher education could be over 24. Additional factors that are likely to influence higher education enrollment are identified, although they are not part of the projection methodology. Assumptions underlying the methodology and the procedures of the methodology are described. (SW)