adoption of new technologies. Although diagnostics account for only 1.6 percent of total Medicare costs, they influence the majority of downstream treatment decisions, so there is a need to assess potential indirect downstream risk and costs. In oncology, the cost of new targeted therapies can be an order of magnitude higher than traditional cancer treatments, and often only a fraction of patients benefit significantly from the treatments. Screening an entire asymptomatic population is also costly and can lead to harm as well as benefit. Biomarkers will be clinically valuable if they encourage appropriate selective use of treatments or identify cancers at a stage that is easier and less costly to treat.