FHIR (Fast Healthcare Interoperability Resources)
What is FHIR?
FHIR is a healthcare-data interchange standard published by HL7 International. FHIR R4 is the version most U.S. health systems deploy today; R5 began limited adoption in 2024. FHIR defines clinical, administrative, and financial resources as RESTful API entities, enabling modern, web-friendly data exchange.
Also: FHIR R4, FHIR R5, HL7 FHIR
FHIR is mandated by the 21st Century Cures Act for patient access, USCDI v3 data sharing, and TEFCA QHIN exchange. BytePad implements FHIR R4 for both ingest (legacy-system retirement) and export (downstream analytics, AI retrieval).
How InterScripts handles this →What is HL7 v2?
HL7 v2 is the messaging standard that has carried 95% of clinical messages between hospital systems since the 1990s, ADT (admit/discharge/transfer), ORM (orders), ORU (results), and SIU (scheduling). Still the dominant real-time integration format inside hospitals.
Also: HL7 2.x, pipe-and-hat
Most legacy EHR retirement programs require HL7 v2 ingest plus translation to FHIR R4 for downstream consumers. BIIG (BytePad Integration & Interoperability Gateway) handles both.
What is USCDI v3?
USCDI v3 is the federally mandated dataset of clinical data classes and elements every U.S. EHR must be able to share via FHIR APIs under the 21st Century Cures Act information-blocking rule. Published by ONC; required for ONC-certified EHRs.
Also: United States Core Data for Interoperability
How InterScripts handles this →What is TEFCA?
TEFCA is the U.S. federal framework for nationwide health information exchange, administered by the Sequoia Project on behalf of ONC. It governs how Qualified Health Information Networks (QHINs) exchange data across the country.
Also: Trusted Exchange Framework and Common Agreement
QHIN (Qualified Health Information Network)
What is QHIN?
A QHIN is a TEFCA-designated network operator authorized to exchange clinical and administrative data nationwide. As of 2026, designated QHINs include eHealth Exchange, Health Gorilla, Epic Nexus, MedAllies, KONZA, CommonWell, and others.
What is C-CDA?
C-CDA is the XML-based clinical-document format defined by HL7 for structured summary documents, Continuity of Care Document (CCD), Discharge Summary, Progress Note, and more. Required by ONC certification.
Also: CCDA, Consolidated Clinical Document Architecture
X12 837 Claims
What is X12 837?
X12 837 is the HIPAA-mandated electronic claims transaction format, 837P (Professional) for physician services, 837I (Institutional) for hospital services. Defined by the ASC X12 standards body.
Also: 837P, 837I
IHE XDS / XDR
What is IHE XDS/XDR?
IHE XDS (Cross-Enterprise Document Sharing) and XDR (Cross-Enterprise Document Reliable Interchange) are the IHE profiles for sharing clinical documents across organizational boundaries, the historical foundation for health information exchanges and a continuing pattern in federal deployments.
Also: Integrating the Healthcare Enterprise XDS