Abstract The Food and Drug Administration (FDA) has been actively involved in oversight of medical devices, including in vitro diagnostic devices (IVDs) since the passage of the Medical Device Amendments of 1976. A variety of both premarket and postmarket regulatory controls were put into place as a result of this new program. The type of oversight applied to tumor markers available for marketing in the United States depends on both the intended use of the test and the manner in which it is being commercialized—whether offered as a test kit or system or as a laboratory testing service. Tumor markers may be reviewed as 510(k) submissions or as premarket approval application (PMA) submissions or may be exempt from premarket reviews. The FDA works hard to maintain an appropriate balance in its oversight activity and to ensure that its mission is focused on activities designed to promote public health. Semin Oncol 29:294-300. This is a US government work. There are no restrictions on its use.