The United States is undertaking an ambitious effort to wire the health care system. The goal is to build a nationwide information infrastructure to serve as the foundation for large and sustained improvements in performance. Widespread adoption of health information technology will support new care delivery models, such as patient-centered medical homes, alongside broader initiatives, such as performance reporting and public health surveillance. To enable the health information technology revolution, Congress allocated nearly $30 billion focused on 2 main goals: transitioning physicians and hospitals from paper-based to electronic systems and enabling these systems to interoperate, allowing clinical data to flow between health care organizations.