hData is a lightweight, web-based specification for exchanging electronic health data. Created in 2009 by US non-profit MITRE Corporation and evolved in cooperation with leaders in the health care industry, hData is the first RESTful standard for health data exchange.

Current electronic health data exchange standards are complex, hard to implement, and difficult to manage, especially for web centric and mobile developers. hData is a flexible web-oriented framework that addresses these issues and lays the foundation for efficient health information exchange. hData not only connects individuals to their health data, it also provides machine-to-machine data exchange.