“Personalized medicine” or more preferred term “precision medicine” is a medical model that separates patients into different subpopulations with medical decisions, practices, interventions and/or products being tailored to the individual patient based on their predicted treatment response or risk of disease. Often such risk or response predication is based on biomarker measured or detected by diagnostic devices (or tests). While the term precision medicine is often interpreted as treatment selection best suited for an individual patient, the term as used in this paper is much broader than that. Personalized medicine can be used for treatment selection, risk prediction, and disease or treatment monitoring. This talk will discuss statistical consideration for device/drug clinical validation for different intended uses of personalized medicine.