As more Americans enter college than ever before, their pathways through the broadly differentiated higher education system are changing. Movement in, out, and among institutions now characterizes students' attendance patterns--half of all undergraduates who begin at a four-year institution go on to attend at least one other college, and over one-third take some time off from college after their initial enrollment. This study investigated whether there is social-class variation in these patterns, with advantaged and disadvantaged students responding to new postsecondary choices by engaging in different pathways. National longitudinal data from postsecondary transcripts were used to follow students across schools and to examine the importance of family background and high school preparation in predicting forms of college attendance. The results demonstrate that students from lower socioeconomic backgrounds are more likely than are economically advantaged students (net of prior academic preparation) to follow pathways that are characterized by interrupted movement. Such pathways appear to be less effective routes to the timely completion of degrees. Thus, differences in how students attend college represent an additional layer of stratification in higher education.