Effective and dynamic recording of radiation exposure and medical diagnostic information for individuals suspected or known to have been exposed to ionizing radiation contributes to appropriate formulation of medical treatment strategies and radiation protection management. The objectives of this article are to report the database entry templates or screens, provide general use guidelines, and discuss the application to selected radiation exposure scenarios for the Armed Forces Radiobiology Research Institute’s software application, Biodosimetry Assessment Tool (BAT). BAT data entry screens were developed based on consensus generic guidance and organized into discrete categories (i.e., physical dosimetry, contamination, prodromal symptoms, hematology, lymphocyte cytogenetics, erythema/wound, and infection) to facilitate its practical use during the early-phase response for radiological incidents. The summary report provides a concise output of information on radiation exposure, radionuclide contamination, dose assessment based on biological indicators (i.e., cytogenetic chromosome aberration bioassays, time to onset of vomiting, lymphocyte cell counts or depletion kinetics), and relevant clinical signs and symptoms. The BAT report template is compliant with NATO and international guidance for recording ionizing radiation exposures for medical purposes.