The US FDA has been regulating medical devices (including laboratory tests) since 1976. Premarket review is well defined and may include requirements for both analytical and clinical information. In 2004, the US FDA initiated the Critical Path initiative to help foster development of new medical products. Biomarkers were seen as an important part of this new program for both traditional diagnostic purposes and to aid in drug development. The US FDA has created programs to foster use of biomarkers both for routine diagnostic and for drug development purposes. There is growing methodology to serve as road maps for efficient and scientifically sound development in this area. The US FDA has a flexible regulatory tool box to apply to biomarker development, and has the clear aim of working as a partner to bring these important medical devices quickly to the medical marketplace.