The Government Accountability Office (GAO) has designated Medicare and Medicaid as high-risk programs, in part due to their susceptibility to improper payments -- estimated to be about $70 billion in fiscal year 2010. Improper payments have many causes, such as submissions of duplicate claims or fraud, waste, and abuse. As the administrator of these programs, the Centers for Medicare and Medicaid Services (CMS) is responsible for safeguarding them from loss. This book explores fraud detection and deterrence in Medicare and Medicaid, with a focus on fraud detection systems; screening providers and suppliers; and program integrity.