Lynch syndrome (LS) is the most common inherited cause of colorectal (CRC) and endometrial cancer. We here define LS as an individual with a germline deleterious mutation in one of the four mismatch repair (MMR) genes MSH2, MLH1, MSH6 and PMS2 or EPCAM [1]. Presently, most people diagnosed with LS have already had colorectal (CRC) endometrial (EC) or other LS-associated cancers; however, among all existing carriers of LS the majority has not (yet) had cancer. LS is currently seriously under-diagnosed. A recent study [2] of stages III and IV CRC patients in the Kaiser Permanente healthcare system found that family history documentation varied from site to site with 3 sites documenting family history on\70% of cases and 4 sites documenting family history in over 85% of cases. Despite the fact that in those with a documented family history, 61% had a relative with cancer and 20% of these had CRC in at least one first degree relative,\5% of the population received any Lynch syndrome testing [2]. There are essentially three different approaches that can be taken to identify individuals with Lynch syndrome:(1) The current approach which is to educate providers about Lynch syndrome and then expect that they take a family history from their patients and refer appropriate patients for a cancer genetics evaluation;(2) screen all newly diagnosed CRC and EC patients for Lynch syndrome at the time of diagnosis; or (3) screen the general public for Lynch syndrome either at birth or in early adulthood. Since it is clear that the current approach is not sufficient alone, we discuss the latter two approaches here.