This study examines the within-niche product proliferation of Masters in Business Administration (MBA) programs. Building on the resource-based view and on the product proliferation literature, we conceptualize business schools’ MBA portfolio offers as dependent on their reputation, and the market segment in which they and their university operate. We test our hypotheses using data on the portfolio of MBA programs offered by the 200 U.S. universities whose full-time MBA programs are listed in the 2015 U.S. News and World Report (USNWR). For the 96 unranked universities, the decision to offer an MBA program seems to be a reflection of the intention to exploit their economies of scale and graduate specialization. Among 104 ranked universities, there seem to be two different rationales. Among the top ranked universities, MBA program portfolio decisions tend to reflect efforts to maintain a high rankings and a research focus; while for lower ranked universities, the decision seems to be based on reputation and graduate specialization. Our results suggest that top ranked compared to lower ranked and unranked universities are less likely to offer online and part-time MBAs and that executive MBA is exclusive to ranked universities. We discuss the implications on the literature and for university deans and administrators.