Unified Medical Language System (UMLS) is a world-renowned medical terminology that integrates multiple semantic standards into a single system enabling interoperability between the semantic standards, which in turn allows applications to translate medical codes from one source to another. Currently, users need to comprehend the complex UMLS knowledge structure and require technical skills to utilize UMLS. There exists no terminology service that expresses the UMLS captured knowledge in an interoperable format that is agnostic to UMLS knowledge structure, hides its complexity, and easy to comprehend. Thus, the goal of this work is to understand how the FHIR standard can be used for an interoperable representation of the knowledge captured by UMLS. This work provides the foundation to build a terminological service that allows interoperable access to UMLS knowledge hiding its complexity and structural details.