The use of clinical decision support systems (CDSS) transforms physicians’ decision-making process and therewith their competency. Some physicians have concerns about using such systems, while others using them experience improved outcomes such as increased efficiency. Physicians’ competency, particularly in the domains of medical science and clinical practice, serves as a bridge between the use of CDSS and the anticipated outcomes. This connection is relatively unexplored. As physicians’ competency fields are an important puzzle piece within the transformation of the decision-making process, our aim is to identify how CDSS change physicians’ tasks and affect their competency. After deriving a competency framework for physicians, our contribution is to explain the effect of the use of CDSS on physicians’ competency. Our findings indicate personal, sociotechnical, and medical factors moderating physicians’ use of CDSS.