A key mission of the International Atomic Energy Agency (IAEA) is promoting the peaceful uses of nuclear energy through its Technical Cooperation (TC) program, which provides equipment, training, fellowships, and other services to its member states. The United States provides approximately 25 percent of the TC program's annual budget. This report addresses the (1) extent to which the United States and IAEA have policies limiting member states' participation in the TC program on the basis of nuclear proliferation and related concerns; (2) extent to which the United States and IAEA evaluate and monitor TC projects for proliferation concerns; and (3) any limitations and challenges in IAEA's management of the TC program. To address these issues, GAO interviewed relevant officials at the Departments of State (State) and Energy (DOE) and IAEA; analyzed IAEA, DOE, and national laboratory data; and assessed State and IAEA policies toward the TC program. GAO is asking Congress to consider requiring State to withhold a proportionate share of its contributions to the TCF for TC program assistance provided to U.S.-designated state sponsors of terrorism or to report to Congress on its rationale for not withholding a proportionate share of its TCF contribution for such countries. State opposed a proportionate withholding requirement.