This paper describes the history, current status, and objectives and potential impact of the new National Institute of Biomedical Imaging and Bioengineering (NIBIB). Three of the authors (Hendee, Chien, and Maynard) have been involved over several years in the effort to raise the identity of biomedical imaging and bioengineering at the National Institutes of Health. The fourth author (Dean) is the Acting Director of the newly formed NIBIB. These individuals have an extensive collective knowledge of the events that led to formation of the NIBIB, and are intimately involved in shaping its objectives and implementation strategy. This special report provides a historical record of activities leading to establishment of the NIBIB, and an accounting of present and potential advances in biomedical engineering and imaging that will be facilitated and enhanced by NIBIB. The National Institute of Biomedical Imaging and Bioengineering represents a "coming of age" of biomedical engineering and imaging, and offers great potential to expand the research frontiers of these disciplines to unparalleled heights.