A supply of enriched uranium is crucial to support the nation’s nuclear weapons stockpile and the U.S. Navy, but the infrastructure of several U.S. uranium- processing facilities is outdated. In 2014, NNSA began plans to meet the nation’s uranium needs by redirecting processing capabilities to the UPF and to other existing buildings NNSA plans to upgrade at Y-12 in Oak Ridge, Tennessee. This report, which is GAO’s sixth on the UPF, examines (1) the status of the UPF project and plans for starting UPF operations; (2) the extent to which NNSA has followed requirements to obtain independent cost estimates for the UPF, and how NNSA has used information from those estimates; and (3) the extent to which NNSA has made progress in developing uranium program management information since GAO’s September 2017 report.