Abdominal aortic aneurysms are relatively common and often life-threatening, with especially high mortality after aneurysm rupture. The introduction of endovascular aneurysm repair, a minimally invasive alternative to traditional open repair, led to decreased mortality and morbidity in randomized controlled trials, but these trials were conducted in highly selected patients and providers and were underpowered to detect differences in rare adverse events throughout follow-up. With observational studies of Medicare beneficiaries, we demonstrate that the randomized trial results are generalizable to the majority of patients undergoing abdominal aortic aneurysm repair in the United States. Additionally, with a larger cohort, comparative analyses evaluating rare, previously unstudied late outcomes such as laparotomy-related complications, late reinterventions, mortality with reinterventions, and late rupture could be conducted. Furthermore, trends in management over time and relationships between surgeon and hospital volume and outcomes can be studied. The goal of this review was to summarize the existing literature regarding abdominal aortic aneurysms among Medicare beneficiaries and to evaluate the benefits and limitations of administrative claims data in comparative effectiveness research.