Health Information Exchange (HIE) between organizations is necessary to have more complete information and coordinate care. Given its nationwide footprint, the Department of Veterans Affairs (VA) connects and exchanges health information with a large number of organizations and consequently has a unique opportunity to experience most issues affecting clinical interoperability. The Veterans HIE Program manages these exchanges by focusing on patient engagement, provider adoption, partner relationship, technology platform, and performance. This paper analyzes the success and challenges of this program over the last five years, and offers valuable metrics and insights. Although significant progress has been made, nationwide interoperability remains fragmented and laborious, requiring multiple agreements and exchange methods. A future nationwide interoperability would embrace a single "on-ramp" to connect to everyone.