In 2009, the Centers for Medicare & Medicaid Services publicly reported hospital-level risk-standardized 30-day mortality and readmission rates after acute myocardial infarction (AMI) and heart failure (HF). The authors calculated 30-day mortality and readmission rates for all Medicare fee-for-service beneficiaries ages 65 years or older with a primary diagnosis of AMI or HF, discharged between July 2005 and June 2008. The median 30-day mortality rate was 16 percent for AMI and 11 percent for HF. The median 30-day readmission rate was 20 percent for AMI and 24 percent for HF. Risk-standardized mortality rates for AMI and HF varied among hospitals and across the country, and readmission rates were particularly high.