 information about potential cancer risk factors and biological markers. In the next decade, these cohorts will reach the end of their natural lifetime due to the length of time since the baseline questionnaire, the average age of the participants, and the depletion of biological samples. There is the need, therefore, to start planning for the next generation of cohorts that will be able to continue to address current and future hypotheses about the etiology of cancer. A working group within DCEG was formed to discuss potential settings, and a cohort study within the US military setting was selected as one of the promising possibilities. Attractive features conducive to conducting a cohort study using the TriCare health insurance system was the possibility of linkage to numerous electronic databases, including those that maintain addresses and enrollment status, pharmacy databases, medical records databases, and cancer registry and mortality databases. Tricare is a health care insurance program for uniformed service members active, GuardReserve, retired and their families. 