With the arrival of the information age and transition to- wards Electronic Health Records (EHR) and Digital Data, the need for aggregating data across multiple sources lead to the concepts of interoperability. Initially, interoperability was de ned only from the perspective of technical inter- operability and semantic interoperability. Over time, what was required to make things work together expanded the concepts of the scope of this topic. Unfortunately, the momentum of what currently exists, lack of motivation to change, the cost of change, and lack of a clear Return on Investment (ROI), and unclear solutions has made interop- erability seemingly an impossible goal. This paper postulates that the de nition of interoperability varies based on use case. The paper discusses what adjectives the term interoperability might legitimately carry {total, partial, implied, . . . The paper also discusses the problems associated with a focus on the word interoperability and attempting to create standards that enable the concept rather than a focus on what we are really trying to do and then looking at what is required to make that happen. Finally, the paper discusses the recent Request for Information (RFI) from the U.S. Office of the National Coordination (ONC) for Health Information Technology to provide suggestions about how interoperability might be measured.