Shared decision making (SDM) is an approach to medical care based on collaboration between provider and patient, with both sharing in medical decisions. When patients' values and preferences are incorporated in decision making, care is more appropriate, ethically sound, and often lower in cost. However, SDM is difficult to implement in routine practice because of the time required for SDM methods, the lack of integration of SDM approaches into electronic health record (EHR) systems, and absence of explanatory mechanisms for providers on the results of patients' use of decision aids. This article discusses potential solutions, including the concept of a "personalize button" for EHRs. Leveraging a 4-phase clinical model for SDM, this article describes how computer decision support (CDS) technologies integrated into EHRs can help ensure that health care is delivered in a way that is respectful of those preferences. The architecture described herein, called CDS for SDM, is built on recognized standards that are currently integrated into certification requirements for EHRs as part of meaningful use regulations. While additional work is needed on modeling of preferences and on techniques for rapid communication models of preferences to clinicians, unless EHRs are redesigned to support SDM around and during clinical encounters, they are likely to continue to be an unintended barrier to SDM. With appropriate development, EHRs could be a powerful tool to promote SDM by reminding providers of situations for SDM and monitoring ongoing care to ensure treatments are consistent with patients' preferences.