Hospital readmissions often look like a golden opportunity to achieve the elusive triple aim of improved patient experience, better population health, and lower costs. Programs to better coordinate transitions from hospital to home could produce positive returns if they could reduce a small fraction of those repeat hospitalizations. Under the Affordable Care Act, Medicare is now reducing reimbursements to hospitals that exceed national averages for all-cause readmission rates for 6 conditions: acute myocardial infarction, heart failure, pneumonia, joint replacement, chronic lung disease, and cardiac bypass surgery. Not surprisingly, every hospital in the United States has been focusing intently on how best to reduce preventable readmissions, and 30-day rehospitalization rates fell from 58.2 to 50.1 per 1000 Medicare beneficiaries between 2009 and 2013.1