Over the last four decades, the UK has made large investments in healthcare information technology. The authors conducted interviews and reviewed published and unpublished documents to describe national-scale clinical information exchange in England, how it was achieved, and the problems experienced that the USA might avoid. Clinical information exchange in the UK was accomplished by establishing a foundation of policy, infrastructure, and systems of care, by creating and acquiring clinical computing applications and with strong use of financial and clinical incentives. Many software and hardware vendors played a part in this effort; they participated in a national framework created by the NHS in which standards for exchange are specified and their applications designed to make clinical information exchange part of normal practice. Great potential exists for cost reduction, increased safety, and greater patient involvement as a result of clinical information exchange.