Abstract The goal of personalized medicine is to find the right medicine for the right person at the right time. Although this concept has been widely heralded as the future of medicine, only now are we beginning to see the first examples of personalized medicine at work. In this article, we discuss examples of personalized medicine that use in vitro diagnostic (IVD) tests. IVD tests have always been useful in guiding therapy; the difference is that in personalized medicine, many more aspects of disease management can be addressed through in vitro testing. In time, personalized medicine will affect all aspects of medicine from risk assessment to response monitoring.