The introduction of science into the practice of medicine in the early 20th century was a transforming event for the profession. Now, breakthroughs in science and know how make it possible to transform care once again and to fix the broken US health care system. To realize this potential, new models of prospective health care must be created and validated. Prospective health care would determine the risk for individuals to develop specific diseases, detect the disease’s earliest onset, and prevent or intervene early enough to provide maximum benefit. Each individual would have a personalized health plan to accomplish this. Current knowledge is already sufficient to implement this approach, but there are no effective practice models, delivery systems, and appropriate reimbursement mechanisms.