As part of President Obama’s Precision Medicine Initiative (PMI), the National Institutes of Health will award $142 million over five years to the Mayo Clinic, Rochester, Minnesota, to establish the world’s largest research-cohort biobank for the PMI Cohort Program, a longitudinal research study which aims to enroll 1 million or more U.S. participants to advance precision medicine. The award will support the collection, storage and distribution for research use of biological samples known as biospecimens. Laboratory analyses of the biospecimens, including chemical and genetic tests, will be a key component of the core PMI Cohort Program data set. These data, combined with other information provided by volunteers such as lifestyle and health questionnaires, medication history, electronic health records, physical exams, and environmental exposures and real time physiology tracked through mobile health technologies, will help researchers study individual differences in health and disease.