Data from the postsecondary transcripts of high school seniors included in the High School and Beyond (HS&B) study of the class of 1980 and the National Longitudinal Study (NLS) of the Senior Class of 1972 were analyzed to investigate the participation of students in two-year postsecondary programs. The analyses focused mainly on the characteristics of students who received an associate degree or certificate in a vocational education program within 4 years of high school graduation. Study findings included the following: (1) only 12% of the HS&B graduates who attended any postsecondary institution completed a vocational degree or certificate program; (2) among the 1980 high school seniors who completed a postsecondary program within 4 years of high school graduation, vocational credentials were earned at a rate four times that of academic degrees; (3) HS&B students completed vocational degrees at a higher rate than NLS students, but academic degrees at a lower rate; (4) most associate vocational degrees were completed at public two year colleges; (5) the most popular field of study for vocational program graduates was business, followed by technical and engineering studies and health for associate degree recipients, and trade and industry and health for certificate completers; (6) 40% of all credits earned by vocational degree completers were in academic subjects; (7) students with certificates earned slightly more than half as many credits as students completing vocational degree programs; and (8) the postsecondary credit patterns for those who completed vocational certificate programs and those who completed academic degree programs did not change much between the early to middle 1970's and the early to middle 1980's. Technical notes, data tables, and a classification of postsecondary courses are included in the report. (JMC)