During the past decade, the incidence and mortality associated with acute myocardial infarction (AMI) in the United States have decreased substantially. However, it is unknown whether these improvements were consistent across communities of different economic status and geographic regions since efforts to improve cardiovascular disease prevention and management may have had variable impact. The objective of the study was to determine whether trends in US county-level, risk-standardized AMI hospitalization and mortality rates varied by county-based median income level.