The objective of this study is to evaluate a new Northern California screening program for abdominal aortic aneurysm (AAA) in terms of its effect among relevant patients on their AAA-related outcomes of care and processes of care. Aneurysms of the infrarenal portion of the abdominal aorta are generally asypmptomatic until they rupture, an event that is usually fatal. Clinical trials have shown that, despite the risk associated with interventions, repair of the aneurysm results in a lower overall and cardiovascular mortality among male smokers, aged 65-75. KPNC will invite all members in this group to a one-time ultrasound screening appointment in a stepped fashion across all facilities. We will take advantage of this stepped program implementation to investigate the effect of an invitation to screening vs. the control membership awaiting screening; the primary outcomes are total mortality, AAA-related mortality and the need for emergent surgery for a ruptured AAA.