From 1945 through 1962, the US atmospheric nuclear weapons testing program involved hundreds of thousands of military and civilian personnel, and some of them were exposed to ionizing radiation. Veterans' groups have since been concerned that their members' health was affected by radiation exposure associated with participation in nuclear tests and have pressured Congress for disability compensation. Several pieces of legislation have been passed to compensate both military and civilian personnel for such health effects. Veterans' concerns about the accuracy of reconstructed doses prompted Congress to have the General Accounting Office (GAO) review the dose reconstruction program used to estimate exposure. The GAO study concluded that dose reconstruction is a valid method of estimating radiation dose and could be used as the basis of compensation. It also recommended an independent review of the dose reconstruction program. The result of that recommendation was a congressional mandate that the Defense Threat Reduction Agency (DTRA), a part of the Department of Defense, ask the National Research Council to conduct an independent review of the dose reconstruction program. In response to that request, the National Research Council established the Committee to Review the Dose Reconstruction Program of the Defense Threat Reduction Agency in the Board on Radiation Effects Research (BRER). The committee randomly selected sample records of doses that had been reconstructed by DTRA and carefully evaluated them. The committee's report describes its findings and provides responses to many of the questions that have been raised by the veterans.