Hospital-acquired conditions (HACs) are thought to be preventable, and the Centers for Medicare and Medicaid Services reduces payments to hospitals with the highest rates of these conditions. This analysis sought to assess the association between measures of hospital quality, such as accreditation, and penalties for HACs. Researchers found that accredited hospitals were more likely to incur HAC penalties. Teaching institutions, hospitals whose case mix included more complex patients, and safety-net hospitals were all more likely to face penalties than nonteaching, nonsafety institutions with healthier patients. These results add weight to concerns about unintended consequences of pay-for-performance programs leading to widening health disparities and selective treatment, or "cherry-picking" of healthier patients. A related editorial co-authored by two United States Senators calls for including socioeconomic status in the HAC penalty formula.