The MidSouth eHealth Alliances health information exchange in Memphis, Tennessee provides access to data on almost 1 million individuals. The effort is the product of a comprehensive, integrated approach to technology and policy that emphasizes patient-centered use, low-cost, flexibility, and rigorous privacy and confidentiality policies and practices It is used in emergency departments and other major clinical settings. This paper provides a high-level overview of the system and its use. The early anecdotal success of this effort and preliminary formal clinical and financial evaluation suggest that health information exchanges can improve care at relatively low cost.