Emergency physicians often must make critical, time-sensitive decisions with a paucity of information with the realization that additional unavailable health information may exist. Health information exchange enables clinician access to patient health information from multiple sources across the spectrum of care. This can provide a more complete longitudinal record, which more accurately reflects the way most patients obtain care: across multiple providers and provider organizations. This information article explores various aspects of health information exchange that are relevant to emergency medicine and offers guidance to emergency physicians and to organized medicine for the use and promotion of this emerging technology. This article makes 5 primary emergency medicine-focused recommendations, as well as 7 additional secondary generalized recommendations, to health information exchanges, policymakers, and professional groups, which are crafted to facilitate health information exchange's purpose and demonstrate its value.