At the request of the National Institute of Standards and Technology (NIST), the National Academies of Sciences, Engineering, and Medicine has, since 1959 annually assembled panels of experts from academia, industry, medicine, and other scientific and engineering environments to assess the quality and effectiveness of the NIST measurements and standards laboratories, of which there are now seven, as well as the adequacy of the laboratories’ resources. An Assessment of the National Institute of Standards and Technology Center for Neutron Research: Fiscal Year 2015 reviews the organization’s technical programs, the portfolio of scientific expertise within the organization, the adequacy of the organization’s facilities, equipment, and human resources, and the effectiveness with which the organization disseminates its program outputs.