Major theoretical approaches to the study of career mobility were reviewed, with particular emphasis on those that focus on the organizational-structural level of analysis, on careers as structures of organizations. In particular, internal labor market theory was explored as a framework through which to study administrative careers in colleges and universities. Three elements (a job ladder or career line, entry ports, and movement up the ladder or career lines) identified as constituting an internal labor market provided specific focus of attention. Colleges and universities are special types of organizations with no clearly defined career lines. Consequently, there are few clearly defined steps in the line to the presidency or to the top-level position in a functional area such as student affairs. Using data from "Today's Academic Leaders: A National Study of Administrators in Community and Junior Colleges" (Pennsylvania State University, 1984), career paths were charted for four positions--president, chief academic officer, chief student affairs officer, and chief business officer. An analysis of the data found that top-level administrators were likely to have come from within two-year colleges rather than from outside or from four-year colleges; however, most had held positions in four-year colleges at some point. Chief business officers often moved directly to their current positions from outside postsecondary education. This study shows that career lines do develop over time. Further research on career lines in higher education is needed so that persons going into academic administration, particularly women and minorities, can gain a clearer picture of what steps to follow in order to advance to top administrative positions. Three tables and a reference list of six pages are provided. (KC)