During the performance of dose reconstructions, individual dosimeter data and measured intakes (through bioassay analysis, in vivo measurements, etc.) should be used whenever possible and given precedence over area monitors, survey data, or source term data. However, this is not always possible. A person's exposure record may be incomplete, missing, or perhaps the individual was not monitored properly or at all during the time of employment. The development of site profiles for all of the major Department of Energy and many Atomic Weapons Employer (AWE) sites over the last two years has been an important part of the Dose Reconstruction project for NIOSH. Approximately 20 profiles have been completed to date with another 25 currently being worked on or planned for completion by the end of the year. These site profiles serve several purposes including 1) the identification of the facilities on site with a brief description of the processes and radionuclides of interest; 2) support information for the dose reconstructor to use if the monitoring data are inadequate or not available (i.e., occupational medical, environmental, internal dosimetry, and external dosimetry exposure information); 3) supporting information (e.g., Technical Information Bulletins (TIBs), databases, executable files) that support the performance of dose reconstructions for workers from a specific site.