Potentially preventable readmissions (PPRs) among Medicare patients are examples of inefficiencies in the healthcare system. Policymakers are considering efforts to measure and publicly report preventable readmission rates and target hospitals with high rates for improvement by means of payment policy and technical assistance. To help inform the policy debate about readmissions of rural patients, this study estimated PPRs in three types of acute care hospitals: urban prospective payment system (PPS) hospitals, rural PPS hospitals, and Critical Access Hospitals.