As healthcare becomes increasingly digital, the need for systems to communicate seamlessly is more crucial than ever. Enter the world of health interoperability standards with names like HL7, FHIR, and SNOMED CT leading the charge. 

But what do these terms mean? How are they different? And why do they matter for better patient care, data exchange, and digital transformation?  

Let’s examine the roles of HL7, FHIR, and SNOMED CT and why they are foundational to modern, connected healthcare systems.  

What is HL7?  

Health Level Seven (HL7) is a non-profit organisation that creates and maintains international standards.  

HL7 standards refer to international standards for exchanging, integrating, sharing, and retrieving electronic health information. HL7 standards help ensure that healthcare systems, like electronic medical records (EMRs), lab systems, and pharmacy systems, can “speak the same language.”  

Key features:  

  • Enables data exchange between healthcare software systems  
  • Includes multiple standards (e.g., HL7 v2, HL7 v3) used globally  
  • Widely adopted in hospitals, labs, and primary care  

Why HL7 standards matter:  

The HL7 v2 standard has been a workhorse of healthcare messaging for decades, used for everything from admission and discharge messages to lab orders and billing.  

Explore more about what HL7 is and why healthcare needs it.  

However, HL7 v2 is not suitable for modern web applications or ecosystems, leading us to a modern specification: FHIR.  

What is FHIR?  

FHIR (Fast Healthcare Interoperability Resources) is a newer standard developed by HL7. It’s designed to support modern, web-based healthcare data exchange, using the same technologies that power today’s apps and APIs.  

Key Features:  

  • Built using RESTful APIs, JSON, and XML  
  • Enables real-time access to health data across systems and devices  
  • Highly flexible and developer-friendly  
  • Ideal for patient apps, health information exchanges (HIEs), and digital front doors  

Why FHIR is important:  

FHIR is the future-facing standard enabling interoperable, patient-centred care. It’s behind many innovations in digital health apps, telehealth, and value-based care reporting.  

Learn more on the basics of FHIR in this blog  

What is SNOMED CT?  

SNOMED CT (Systematised Nomenclature of Medicine – Clinical Terms) is a comprehensive, multilingual clinical terminology system. It standardises healthcare language, ensuring that clinicians and systems record information in a consistent and computable manner. 

Key Features:  

  • Provides standard codes and concepts for diseases, procedures, body structures, symptoms, and more  
  • Enables accurate data exchange, mapping, and aggregation  
  • Is mapped to other international standards 

Why SNOMED CT matters:  

SNOMED CT enables consistent clinical documentation and supports interoperability between health IT systems by serving as a common language for validated clinical content. Its structured, computable format enhances the effectiveness of clinical decision support tools, enables meaningful data exchange across care settings, and underpins analytics and research efforts by allowing for accurate data aggregation and interpretation. Internationally adopted and preferred within the FHIR standard, SNOMED CT facilitates regulatory reporting, improves patient safety, and plays a foundational role in advancing precision medicine, population health, and value-based care. 

SNOMED CT is especially critical in:  

  • Electronic Health Records (EHRs)  
  • Clinical decision support tools  
  • Population health analytics  
  • AI and machine learning models  

SNOMED is maintained by SNOMED International and is used in over 50 countries. Learn more: https://www.snomed.org  

HL7 vs FHIR vs SNOMED CT: How they work together  

These standards aren’t in competition—they serve different but complementary roles in the health data ecosystem.  

Standard Role Focus 
HL7 (v2) Messaging protocol for health systems Data exchange between systems 
FHIR API-based modern data sharing Real-time access, app development 
SNOMED CT Clinical terminology/coding system Standardised health vocabulary 

Think of it this way:  

  • HL7 v2/FHIR = How data moves between systems 
    • HL7 v2 = how data is ingested 
    • FHIR = how data is accessed/shared  
  • SNOMED CT = What the clinical terms mean 

FHIR and HL7 v2 provide the plumbing for data exchange, while SNOMED CT ensures the content is accurate, consistent, and valuable.  

Why it all matters for connected care  

For healthcare to be truly interoperable, it’s not enough to exchange data; we must also understand and use it effectively. That’s where HL7 v2, FHIR, and SNOMED CT intersect:  

  • FHIR enables mobile apps to pull data from EHRs using standard APIs.
  • SNOMED CT ensures those data points are coded in a common language.
  • HL7 v2 supports legacy systems that still feed data for a large part of hospital infrastructure. 

Together, they power everything from digital front doors to clinical decision support, remote monitoring, and population health analytics.  

Looking to understand how HL7 v2, FHIR, and SNOMED CT support national interoperability initiatives? Explore Orion Health’s Interoperability solutions.  

HL7 v2, FHIR, and SNOMED CT are pillars of a connected, intelligent health system. Understanding how they work and work together is key to unlocking better data, insights, and care.  

At Orion Health, we help health systems worldwide build modern interoperability frameworks using standards like FHIR, HL7 v2, and SNOMED CT to deliver smarter, more efficient, and more personalised care.  

Want to explore how to strengthen your interoperability strategy?

Talk to our team