Background/Context: The analysis contained in this article was commissioned by the Social Science Research Council's Transitions to College project. Although the historical context and contemporary issues associated with English learners (ELs) and undocumented immigrant students are in many ways distinct, the project team strongly believed that the college transition issues affecting these populations were increasingly salient in light of their rapid and continued growth throughout the United States. Purpose/Objective/Research Questions/Focus of Study: The research questions guiding this analysis are: (1) What do we know and what do we need to know about the transition to college of EL and undocumented immigrant students? and (2) What are the resource and policy implications associated with the transition to college of these students? The chief purpose of this analysis is to synthesize the current research and thinking about the transitions to college of EL and undocumented immigrant students and to use the findings to develop a research agenda focused on emergent critical issues. The intent is to educate a research audience that is largely unfamiliar with the experiences of these unique populations and to inform future research directions. Research Design: The analysis is situated within the broader context of immigrant educational attainment and integration in the United States. The two student populations are distinguished to delineate the particular college transition experiences of ELs versus undocumented students, while recognizing the overlaps that do exist. Thus, for each student population, the analysis synthesizes current literature and provides discussions of (a) student demographics for states and the United States, (b) student-level issues and factors, (c) K-12 issues and factors, (d) student agency, (e) postsecondary issues and factors, and 09 summary of critical challenges, barriers, and accomplishments relative to the college transition. The final element is a recommended research agenda developed from the issues revealed in this analysis. Findings/Results: There is continued growth in the presence of EL and undocumented students, and this growth affects states with longstanding histories of immigrant presence, as well as states that have only recently had notable increases in these populations. Important to understanding the needs and potential of these two groups is that not all EL and undocumented students are new immigrants. Rather, many have only experienced education in the United States, having been born here or having arrived at a very young age with their families. From this analysis, it appears that English proficiency is as much a gatekeeping factor as it is a facilitative factor for EL and undocumented students in their successful college transitions. Unfortunately, because of the impact of poverty on these populations, the financial constraints of transitioning to college further compound the challenges already faced with regard to acquiring English and advanced subject matter proficiency. Two additional findings help to frame the college transition challenges of both EL and undocumented student populations: (i) There is a chasm between research-based best practices and the available human and material resources allocated in schools and colleges to support this objective, and (2) the role of the community college system is salient as a potential facilitative context, but one that is currently overburdened with multiple demands and shrinking resources. Conclusions/Recommendations: The article presents an eight-point research agenda that addresses the challenges surfaced in the analysis. The points cover K-12 education, evaluations of the impact of legislation and programs, and postsecondary education, with the aim of improving the overall responsiveness of our educational institutions to the needs and strengths of our EL and undocumented student populations. [ABSTRACT FROM AUTHOR]