Why is our health care system so fragmented in the care it gives patients? Why is there little coordination amongst the many doctors who treat individual patients, who often even lack access to a common set of medical records? Why is fragmentation a problem even within a single hospital, where errors or miscommunications often seem to result from poor coordination amongst the myriad of professionals treating any one individual patient? Why is health care fragmented both over time, so that too little is spent on preventive care, and across patients, so that resources are often misallocated to the patients who need it least? The Fragmentation of U.S. Health Care: Causes and Solutions approaches these broad questions with a highly interdisciplinary approach. The articles included in the work address legal and regulatory issues, including laws that mandate separate payments for each provider, restrict hospitals or others from controlling or rewarding the set of providers treating a patient to assure coordinated care, and provide affirmative disincentives for coordinating care by paying more for uncoordinated care that requires more services. Business reasons for the current form of hospital organization are considered, and efficiency and design are examined and compared to other industries. The economics of current hospital organization are also taken into account. The authors examine and propose various reforms that make our health care system less fragmented, more efficient, and more medically effective.