The Health Records Enhancement Act requires the Secretaries of Defense and Veterans Affairs to jointly implement a system allowing for the supplementation of deceased veterans' health records within one year. This system will enable the addition of observed health conditions and other relevant health information to the records of individuals who were enrolled in the VA patient system or TRICARE at the time of their death. Updates can be provided by an individual previously designated by the deceased enrollee, or if no such designation exists, by an immediate family member. The bill specifies that these additions will supplement the existing health records and will not modify any information already contained within them. The Secretaries must also establish a clear process for enrollees to make such designations.