The HHS Office of the National Coordination for Health Information Technology (ONC) has published an advance notice of proposed rulemaking soliciting public comments on metadata standards that will support nationwide electronic health information technology exchange. The ONC seeks public input on patient identity, provenance, and privacy metadata, along with comments on any additional metadata categories, elements, or syntax that should be considered. Of particular interest is the association of metadata with summary care records, such as when a patient obtains a summary care record from a health care provider’s electronic health record technology or requests that it be transmitted to their personal health record. Comments are due by September 23, 2011.