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Comparing HL7 & FHIR Standards to Enhance Interoperability in Healthcare

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The global Internet of Medical Things (IoMT) market is expected to become 4x bigger in the next 7-8 years. In 2020, it was worth less than $40 billion, but by 2030, it is predicted to reach over $170 billion. This massive growth is because the IoMT devices and services simplify the creation and sharing of patients’ vital information without human involvement.

Internet of medical things market size, 2020 to 2030 (USD billion)
Figure 1. Internet of medical things market size, 2020 to 2030 (USD billion)

But with such a rapid growth of the market and the amount of patient data circulating on it, effective healthcare data management and exchange of electronic health records (EHRs) have become vital for excellent healthcare delivery. However, this also increases the need for secure and reliable data sharing. 

The healthcare tech market expansion has led to the development of interoperability standards, including Health Level 7 (HL7) and Fast Healthcare Interoperability Resources (FHIR), created by HL7 International. Thus, this article explores the similarities and differences between HL7 and FHIR to help readers select the appropriate standard for their organization upgrade.

“Through our expertise and dedication, the SPsoft team has successfully implemented FHIR solutions that have revolutionized how our clients’ healthcare organizations handle data. Implementing medical data exchange standards has enabled them to experience the tangible benefits of FHIR, witnessing streamlined workflows, reduced costs, and accelerated innovation.”

Romaniya Mykyta
Head of Product Management, SPSoft

“The feedback we have received from our clients speaks volumes about our commitment to excellence. They have praised our in-depth understanding of the healthcare industry, our ability to tailor solutions to their specific needs, and the seamless integration of FHIR into their existing systems. At SPsoft, we are committed to delivering exceptional results, leveraging our expertise, and providing ongoing support to ensure the continued success of our clients.”

Mike Lazor

A healthcare application in use

HL7 and FHIR: The Main Differences

HL7, which stands for Health Level Seven, is a widely recognized and well-established standard in the healthcare industry. It has been used for several decades and has undergone multiple versions and updates. 

HL7 follows a traditional, document-centric approach to healthcare data interoperability. It focuses on exchanging entire documents or messages between healthcare systems, such as patient records, lab results, or medical reports. These documents are structured using HL7’s own messaging and data representation standards.

HL7 vs FHIR: Which is better?

On the other hand, HL7 FHIR certification, which stands for Fast Healthcare Interoperability Resources, is a more modern and vast healthcare data exchange standard. The HL7 FHIR data model is resource-centric, emphasizing separate data elements or resource exchange rather than complete documents. 

FHIR represents healthcare data as a set of modular and interoperable resources, such as patient demographics, vital signs, medications, or allergies. These resources are designed to be easily shared across different systems and platforms. So overall, FHIR offers a more modern and flexible approach, making it suitable for organizations looking to adopt a more up-to-date interoperability framework.

Of course, both HL7 vs FHIR have their strengths and applications, and the choice depends on factors like organizational needs, interoperability requirements, and scalability potential.

What Are HL7 and FHIR? A Concise Overview

Here is a more detailed overview of the HL7 vs FHIR standards.


As a well-established standard, HL7 is used in various healthcare domains, including electronic health records (the use of which grew from 18% in 2001 to 88% in 2021), as well as laboratory and billing systems.

HL7 has different versions, with HL7 v2 being the most widely adopted and using a structured format for message exchange. HL7 v3 and HL7 CDA are more complex and represent clinical information within a structure.

How HL7 works
Figure 2. How HL7 works

HL7 v2

HL7 v2 is a widely adopted messaging standard designed to facilitate communication between different systems within a healthcare organization. Developed in 1989, HL7 v2 ensures interoperability at the enterprise level. It enables the transmission of various data types, including patient admissions, discharges, transfers, medical prescriptions, financial transactions, and observation results.

However, HL7 v2 is mainly used for data transmission within a single organization and cannot store healthcare data in databases. It is also not scalable for communication between different healthcare organizations.

HL7 v3

In the early 2000s, the importance of data in automated healthcare workflows encouraged HL7 to develop a more comprehensive messaging standard. So HL7 v3 was introduced as a solution to address the data exchange gaps that v2 was not handling well.

HL7 v3 is built upon a Reference Information Model (RIM), a universal reference model for healthcare data representation. Compared to v2, v3 provides a more robust framework for data exchange, enabling better interoperability among systems. However, because adhering to HL7 v3 standards requires full RIM implementation, using v3 may be complex and costly.


HL7 CDA (Clinical Document Architecture) focuses on exchanging clinical data through standardized document structures. CDA defines the format and characteristics of clinical documents to enable seamless information sharing between patients and healthcare providers. Thus, critical attributes of CDA include persistence, stewardship, the potential for authentication, context, wholeness, and human readability.

How HL7 CDA works
Figure 3. How HL7 CDA works

CDA is primarily used for exchanging patient-related data in various healthcare settings, including hospitals, clinics, and other healthcare organizations. It is a comprehensive source of patient information, covering medical history, medications, insurance details, laboratory results, and more, featuring diverse types of files, from text to images and sounds. 

What Is HL7 FHIR?

Among the four standards developed by HL7 International, the HL7 FHIR standard is more recent. 

How FHIR works
Figure 4. How FHIR works

FHIR resources represent specific healthcare data entities, such as patients, medications, conditions, observations, and procedures, allowing for effortless sharing and integration across different systems, applications, and organizations.

HL7 FHIR certification uses modern web technologies, such as RESTful APIs, JSON, and XML, making developing and implementing interoperable healthcare solutions easier. And FHIR has gained significant popularity due to its flexibility, scalability, and ability to adapt to evolving healthcare needs. It is designed to work alongside existing healthcare standards and can be implemented along with them.

Ready to explore the power of the HL7 FHIR standard for your healthcare organization? Contact SPsoft today to schedule a consultation and discover how our FHIR integration and interoperability services can transform your operations.

The Essential HL7 and FHIR Protocols

Now, after discussing the HL7 FHIR connection, let’s delve into the fundamental protocols associated with these standards.

Clinician performing a lab test


HL7 protocols enable seamless data exchange and interoperability within a healthcare organization, ensuring standardized communication. Here are the HL7 protocols used:

  • Event-Driven Protocol — Events like a patient’s admission, discharge from a healthcare facility, or the need to place an order at a pharmacy trigger this protocol to communicate them between apps and other systems where the data is relevant.
  • Application to Application Protocol — This protocol facilitates communication between two independent applications. The focus is on the messages being exchanged between the apps rather than the specific roles of each application.
  • OSI Level 7 Protocol — This protocol defines the precise format and content of the exchanged data. Typically, a TCP/IP connection is established for message delivery.
  • Exchange Protocol — This protocol outlines data exchange rules without specifying how each application stores or processes the data. But while the database structure should align with FHIR vs HL7 message definitions, it is not mandatory.
  • Standard Protocol — However, using the HL7 standard protocol eliminates the need for custom link creation to establish the connection before exchanging messages with a third-party system and facilitates interoperability.​​


Since FHIR is a more recent development, it uses protocols different from other HL7 standards. Here are the ones that serve as the foundation for interoperability within the HL7 vs FHIR standards:

  • RESTful API — FHIR uses RESTful principles for exchanging data between systems, including standard HTTP methods like GET, POST, PUT, and DELETE, to perform operations on FHIR resources.
  • HTTP(S) — FHIR uses HTTP as the underlying transport protocol for messaging and transmitting data securely over the internet to different applications, systems, and organizations.
  • OAuth (Open Authorization) — FHIR uses OAuth for authentication and authorization. OAuth enables secure access to FHIR resources by allowing authorized parties to obtain and use access tokens.
  • WebSocket — HL7 FHIR certification can also use WebSocket protocol for real-time communication and data exchange between client applications and FHIR servers to enable back-and-forth communication and efficient updates of FHIR resources.
  • SMART on FHIR — This protocol combines the HL7 FHIR standard with the Substitutable Medical Apps, Reusable Technologies (SMART) platform. SMART on FHIR enables the development of healthcare applications that securely integrate with EHR systems and access FHIR resources.

Dive deeper into our comprehensive article on Smart on FHIR integration and explore the possibilities it offers for seamless data exchange and interoperability. Learn about Smart on FHIR’s capabilities, benefits, and implementation guidelines in our guide.

How Are HL7 and FHIR Similar?

How all HL7 standards work together
Figure 5. How all HL7 standards work together

As all HL7 standards aim to facilitate healthcare data interoperability and promote a standardized exchange of information, FHIR vs HL7 share some similarities. Here are some aspects HL7 vs FHIR have in common:

  • Standardization. HL7 and FHIR are standards developed by HL7 International, a widely recognized organization in healthcare. They provide a common framework and guidelines for representing, transmitting, and exchanging medical data.
  • Data interoperability. The primary objective of both HL7 and FHIR standards is to promote interoperability among different healthcare systems and applications. They enable seamless health information exchange, allowing various systems to communicate and share data effectively.
  • Data modeling. Both standards use data models to define the structure and semantics of healthcare information. HL7 has its RIM as the foundation for data modeling, while FHIR has its own resource-centric data model that describes the structure and relationships between different healthcare resources.
  • Healthcare domain coverage. HL7 vs FHIR applies to various healthcare domains, including electronic health records, laboratory, radiology, and pharmacy systems, enabling data exchange across different areas of healthcare.
  • International adoption. Both HL7 and FHIR standards have gained significant international adoption and are recognized as essential for healthcare interoperability. They are used by healthcare organizations, vendors, and developers globally to enable seamless data exchange and integration.

HL7 and FHIR Standards Comparison

Overall, FHIR’s use of modern web technologies, RESTful APIs, and resource-centric data exchange makes it more functional, flexible, and widely adopted than v2, v3, and CDA. However, the latter also have their benefits.

Comparing FHIR vs HL7 v2, v3, and CDA

We compare FHIR with different versions of the HL7 standard, namely HL7 v2, HL7 v3, and HL7 CDA, regarding their approach, functionality, flexibility, and adoption.

1. Approach

A notable difference is that HL7 standards focus on transmitting message- and document-focused clinical data. In contrast, the HL7 FHIR data model employs resources consisting of metadata, text, or bundled collections of information that form clinical documents to store and exchange electronic medical records

follows a message-centric approach, where healthcare information is exchanged through predefined message structurestakes a more comprehensive and structured, RIM-based approach to medical document sharingrelies on standardized document structures for clinical document exchange takes a resource-centric approach, focusing on the exchange of discrete data elements or resources

2. Functionality

Another critical distinction between HL7 and FHIR connection lies in FHIR’s use of RESTful web services and open web technologies like JSON and RDF data formats, which reduce the learning curve for developers and facilitate easier data exchange. Moreover, FHIR’s RESTful API approach promotes interoperability between integrated EHR systems and various devices and systems like mobile healthcare apps, wearables, and others.

relies on specific message formats, segment definitions, and codes for data representation and is widely used for point-to-point communication between systemsuses the HL7 Reference Information Model, defines detailed data models for clinical concepts, and focuses on standardizing the content and structure of clinical documents and messagesprovides a framework for structuring and representing clinical information in XML format and focuses on capturing and sharing comprehensive patient-centric clinical documents, such as discharge summaries or progress notesrepresents healthcare data as modular resources, such as patients, observations, medications, and conditions that can be easily accessed, shared, and integrated using modern web technologies like RESTful APIs

Explore our in-depth article on Epic FHIR integration and discover how to leverage Epic’s support for HL7 FHIR APIs. We provide valuable insights and documentation to help unlock the power of interoperability in healthcare with FHIR API integration.

3. Flexibility

In short, HL7 v2’s customization may cause interoperability challenges, and HL7 v3 and CDA are relatively strict standards. HL7 FHIR certification, in turn, allows for easy customization and extension of resources, allowing for effortless adjusting to the different needs of healthcare organizations.

can be customized and tailored to meet specific implementation needs, but this customization can lead to variations and challenges in interoperability between different systemsits complexity and strict implementation requirements make it almost entirely inflexible and have posed challenges to widespread adoption and implementationdue to its document-centric nature, it is not as flexible as resource-centric standards like FHIRallows for easy customization and extension of resources, making it adaptable to different use cases and evolving healthcare requirements

4. Adoption

Despite being widely adopted and implemented globally, HL7 v2 must be updated. HL7 v3, in contrast, has lower adoption rates due to its complexity, and HL7 CDA was reasonably adopted until the emergence of HL7 FHIR certification started to threaten its popularity. At the same time, FHIR has been widely adopted in the healthcare industry because of the interoperability opportunities it provides.

has been widely adopted and implemented in various healthcare settings globally, but today, it is outdatedhas seen limited adoption compared to HL7 v2 because of its complexity, slower development process, and transition challenges has gained some adoption, but it has reduced due to the emergence of FHIR as a more flexible and modern standardhas gained significant adoption in the healthcare industry due to its modern approach, use of widely accepted web standards, and emphasis on interoperability, so it is being increasingly implemented in EHR systems, mobile apps, research initiatives, and healthcare technology projects

Want to dive deeper into the world of FHIR APIs? Check out our comprehensive article on FHIR API implementation and best practices to learn how FHIR APIs can revolutionize healthcare data exchange and unleash interoperability’s full potential.

Why Choose FHIR Over HL7 

As you can see, both HL7 and FHIR standards have their pros. But FHIR stands out significantly when it comes to flexibility and interoperability opportunities. So what is HL7 FHIR standard’s uncompromisable advantage making it a better choice than the alternatives?

Modern and Web-Based

FHIR uses web technologies such as RESTful APIs, JSON, and XML that align with current industry practices. FHIR’s adoption of these modern web technologies ensures that various applications and systems can easily access, share, and process data. That allows an FHIR-based healthcare data strategy to promote interoperability and foster collaboration across the healthcare ecosystem.

FHIR enhances and simplifies interoperability in healthcare
Figure 6. FHIR enhances and simplifies interoperability in healthcare

Resource-Centric Model

FHIR vs HL7 follows a resource-centric approach, allowing for the exchange of discrete data elements or resources, revolutionizing how healthcare data is exchanged and managed.

In particular, the HL7 FHIR data model enables more precise querying and selective retrieval of specific information. Healthcare systems can request and exchange only the necessary resources, reducing the burden of processing unnecessary data. Thus, FHIR improves efficiency and supports the development of more targeted and personalized healthcare applications and services.

Simplified Implementation

FHIR is also a developer-friendly standard catering to the needs of modern software developers. It provides clear, concise documentation, extensive online resources, and active community support. This developer-friendly nature of FHIR reduces the learning curve and allows developers to customize and extend the standard to meet their specific needs.

Enhanced Interoperability

More than half of top US health systems consider interoperability critical enough to increase their budgeting on this sector this year.

FHIR promotes improved interoperability by focusing on standardized and well-defined resource structures. Its widely understood data formats and RESTful APIs facilitate communication and data exchange between healthcare systems and applications.

As a result, an FHIR-driven system allows patients to take an active role in their healthcare through consumer-friendly apps, accessing medical information conveniently on their preferred devices. In the meantime, insurance companies can use FHIR to supplement claims data with clinical information to ensure accuracy.

Simultaneous Adoption

One of the significant advantages of FHIR is that you do not have to use FHIR to HL7 converter when adopting FHIR. Organizations can integrate FHIR alongside their existing HL7 implementations without replacing the current system completely or trying to convert HL7 to FHIR data and requirements. That allows for a smoother transition to FHIR, maintaining interoperability with legacy systems and ensuring continuity of operations during the transition period.

Industry Momentum

FHIR has gained remarkable industry momentum and faces widespread support from major healthcare organizations and technology vendors. This broad acceptance contributes to FHIR’s rapid and ongoing evolution. Since this momentum signifies FHIR’s potential to become the leading standard for healthcare interoperability, it is preferable to choose FHIR for integration instead of HL7 standards.

Get Started With FHIR With SPsoft 

At SPsoft, we understand the importance of seamless data exchange and interoperability in the healthcare industry. Our team of experienced professionals are experts in FHIR integration and can guide you through every step of the process.

Whether you are a healthcare provider, software vendor, or technology innovator, we have the expertise to help you get started with FHIR. From initial consultation and assessment to design, development, and deployment, we provide end-to-end FHIR solutions tailored to your unique requirements.

With SPsoft as your FHIR partner, you can expect:

  • expert guidance through the entire process of FHIR implementation
  • seamless integration of FHIR into your existing systems
  • scalable solutions designed to grow with your organization
  • security and privacy of patient data
  • ongoing support and maintenance to ensure your FHIR solutions operate at their best performance

Our approach is centered around your success. And together, we can revolutionize healthcare delivery through seamless data exchange and enhanced collaboration.

Final Thoughts

The comparison between HL7 and FHIR standards reveals the significant benefits FHIR brings to the healthcare industry. The HL7 FHIR data model is flexible, developer-friendly, and resource-focused, facilitating interoperability between healthcare systems.  

So choosing FHIR as the standard for healthcare data exchange in your organization is a strategic choice to pursue an efficient and connected healthcare system and improve the quality of patient care.

Ready to take the next step in implementing FHIR integration and interoperability in your healthcare systems? Contact us today to discuss your requirements and discover how our FHIR experts can help you meet your organization’s goals.


What is the difference between HL7 V2 and FHIR?

The main difference between FHIR vs HL7 v2 is their approach to healthcare data exchange. HL7 v2 follows a document-centric approach, where entire documents or messages are exchanged between systems using predefined message structures. FHIR, in turn, takes a resource-centric approach, focusing on exchanging discrete data elements or resources, allowing for better interoperability.

What version of HL7 is FHIR?

FHIR is not a version of HL7 but is a separate standard developed by HL7 International, which developed HL7 v2, HL7 v3, and HL7 CDA. So FHIR stands independently and is often considered prevailing to the existing HL7 standards.

Are FHIR and HL7 standards?

Yes, both FHIR and HL7 are standards in the healthcare industry. There are various versions of the HL7 standard, like HL7 v2, HL7 v3, and HL7 CDA. FHIR is a standalone standard within the HL7 standard family that focuses on modern and resource-centric healthcare interoperability.

What replaced HL7?

A specific standard has not replaced HL7; instead, HL7 has evolved and introduced newer standards, like FHIR. FHIR represents a more modern and flexible approach to healthcare interoperability, focusing on resource-centric data exchange and current web technologies. But other HL7 standards still exist and are used in various healthcare environments.

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