Nearly 20% of Medicare beneficiaries aged 65 and over who were admitted to a hospital in 2005 were readmitted within 30 days following their initial discharge. The Medicare Payment Advisory Commission estimated that these readmissions cost the Medicare program as much as $15 billion per year and that perhaps as much as two-thirds of these readmissions may be preventable. This book provides an overview on the subject of hospital readmissions with a focus on the complexities, reduction efforts and analyses of hospital-acquired conditions. Hospital readmissions are associated with a number of factors and are not necessarily attributable to problems with the quality of patient care, but strong evidence indicates specific interventions to better manage care transitions at the time of hospital discharge could reduce readmissions for certain conditions.