This document is a study guide for the HL7 FHIR Foundation Exam, which assesses candidates' understanding of FHIR specifications and their ability to work with resources, RESTful operations, conformance, terminology, and security basics. It is designed for individuals with an IT background who are pursuing a career in FHIR-based interoperability. The guide outlines the competencies required for the exam, including understanding implementation guides, API behavior, resource model and structure, implementation, and troubleshooting and validation. It provides recommendations for preparation, such as having six months of experience using FHIR and understanding basic concepts of XML/JSON and RESTful APIs. Additionally, the document details the test format, which includes 125 multiple-choice questions to be completed in 3.5 hours, and emphasizes the importance of formal training and knowledge application of the FHIR specification.