Objective: This study evaluated trends in hospitalizations, treatment, and mortality of ruptured abdominal aortic aneurysms (rAAAs) in the United States Medicare population. Methods: The Medicare inpatient database (1995 through 2006) was reviewed for patients with rAAA and AAA by using International Classification of Disease (9th Clinical Modification) codes for rAAA and AAA. Proportions and trends were analyzed by χ2 analysis, continuous variables by t test, and trends by the Cochran-Armitage test. Results: During the study period, hospitalizations with the diagnoses of rAAA declined from 23.2 to 12.8 per 100,000 Medicare beneficiaries (P < .0001), as did repairs of rAAA (15.6 to 8.4 per 100,000; P < .0001). No change was observed in AAA elective repairs. The 30-day mortality rate after open repair of rAAA decreased by 4.9% (from 39.6% to 34.7%; P = .0007 for trend) for the age group 65 to 74 and by 2.4% (from 52.9% to 50.5%, P = .0008) for the age group ≥75. Perioperative mortality after endovascular repair diminished by 13.6% (from 43.5% in 2001 to 29.9% in 2006; P = .0020). Mortality among women was higher than among men (51.1% vs 40.0% in 2006). The demographics of patients treated for rAAA changed to include a greater proportion of women and patients aged ≥75 years. Conclusion: A significant decrease has occurred in the number of patients who have a diagnosis of rAAA and undergo treatment, but there has been no change in repairs of AAA. The perioperative mortality rate has improved due to the introduction of endovascular repair and a small but progressive improvement in survival after open repair for patients aged 65 to 74 years.