Community colleges play a vital role in higher education, enrolling more than one in every three postsecondary students. While their market share has grown over the past 50 years, students' success rates remain low. Consequently, community college stakeholders are searching with mounting urgency for strategies that increase rates of success. We evaluate the effects of one such strategy, learning communities, from a randomized trial of over 1,500 students at a large urban college in the City University of New York (CUNY) system. We find that the program's positive effects on short-term academic progress (credit accumulation) are maintained seven years after random assignment. We find some limited evidence that the program positively affected graduation rates, particularly for those students without remedial English needs, over this time period. While there is not clear evidence that the program improved economic outcomes, this article concludes by offering sobering reflections on trying to detect the effects of higher education interventions on future earnings.