The EHRVA Interoperability Roadmap is available. Here’s how they describe it:
The EHRVA Interoperability Roadmap supports the national goal of interoperable electronic health records and provides a pragmatic, logical plan that will succeed when adopted and implemented by key stakeholders. We provide this Roadmap to mobilize the leadership of healthcare organizations, information technology vendors and other relevant stakeholders to collectively deliver on the vision by incorporating this Roadmap into their plans.
The roadmap is an interesting piece of literature but is not too useful for actually implementing anything specific. They touch on the general problems of interoperability and how industry can get towards a solution without requiring government action. Worth reading.