Hospital readmission rates are an important indicator of patient safety. This cross-sectional study examined whether patients admitted to hospitals with high readmission rates also had higher risks of in-hospital adverse events. Based on a sample of over 46,000 Medicare patients with pneumonia discharged between July 2010 and December 2019 and linked to Medicare adverse event data, researchers found that patients admitted to hospitals with high all-cause readmission rates were more likely to experience an adverse event during their admission.