Understanding HL7 FHIR: The Key to Fast Healthcare Interoperability

17 min read


Health data exchange is essential for healthcare interoperability, enabling seamless communication and sharing of patient information among different systems. The Healthcare Information Exchange Market, estimated at USD 1.97 billion in 2024 and projected to reach USD 3.44 billion by 2029, further underscores the growing importance of efficient and secure health data exchange practices.

HL7 FHIR, or Fast Healthcare Interoperability Resources, is a modern and efficient health data exchange standard developed by Health Level 7 (HL7®), a leading standards development organization. FHIR utilizes an application programming interface (API) and common internet technologies to facilitate the fast and easy exchange of healthcare information. It has become the go-to standard for healthcare interoperability, enabling secure and seamless data exchange, from clinical and administrative data to patient-generated health data.

With HL7 FHIR, healthcare professionals and researchers can leverage the power of data to make informed decisions, improve patient outcomes, and drive advancements in healthcare. Its flexibility, scalability, and focus on interoperability make it an indispensable tool in the digital transformation of healthcare systems.

Key Takeaways:

  • HL7 FHIR is a health data exchange standard that enables seamless communication and sharing of patient information.
  • It was developed by HL7, a leading standards development organization.
  • FHIR utilizes an API and common internet technologies to facilitate fast and efficient data exchange across the healthcare industry.
  • HL7 FHIR is widely adopted by many healthcare professionals, promoting healthcare interoperability and driving advancements in patient care and research.

What is FHIR and why was it created?

FHIR, which stands for Fast Healthcare Interoperability Resources, was created in 2012 by a team of health information technology implementers led by Grahame Grieve, the inventor of FHIR. The team set out to envision a modern approach to health information exchange, aiming to combine the simplicity of existing exchange methods with the power of Internet technologies.

They wanted to create a standard that would be easy for software developers to use, while also promoting interoperability and simplifying application creation in the healthcare market. To do this, they incorporated modern technologies, such as JSON, XML, HTTP, and OAuth, along with existing exchange methods like HL7 v2 messages and Clinical Document Architecture (CDA).

The goal was to ensure that FHIR could seamlessly integrate with existing workflows and systems by building on established standards like HL7 v2 and CDA. By taking this approach, FHIR provides compatibility with legacy systems, allowing for a smooth transition to the new standard while still embracing modern approaches to healthcare information exchange.

Existing Exchange Methods

Modern Technologies

HL7 v2 messages


Clinical Document Architecture (CDA)


HL7 FHIR Message Interface Structure

HL7 FHIR (Fast Healthcare Interoperability Resources) messages are structured to facilitate the easy exchange and interpretation of healthcare information. These messages are composed of several key elements, each serving a specific purpose in the data communication process. Understanding these elements is crucial for healthcare professionals and developers working with FHIR.

Key Elements of a FHIR Message Interface

  • ResourceType: This defines the type of resource (e.g., Patient, Observation). Each resource type has a specific structure and set of data elements relevant to the type of information it contains.
  • Identifiers: These are unique identifiers for the resource, such as patient ID, which are crucial for tracking and referencing.
  • Meta: This element contains metadata about the resource, including version, language, and profile information.
  • Narrative: A human-readable summary of the resource, often provided in HTML format.
  • Data Elements: These are the specific data points contained within the resource, such as a patient’s name, date of birth, or medical condition.
  • Extensions: FHIR allows for custom extensions to add additional information that is not covered by standard data elements.
  • Links: Resources can include links to other related FHIR resources.

FHIR Message Code Sample

Below is a simplified example of a FHIR message in JSON format representing a Patient resource:

{  "resourceType": "Patient",  "id": "example-patient",  "meta": {    "versionId": "1",    "lastUpdated": "2024-01-01T12:30:00Z"  },  "text": {    "status": "generated",    "div": HTML CODE HERE  },  "identifier": [    {      "system": "",      "value": "P1234"    }  ],  "name": [    {      "use": "official",      "family": "Doe",      "given": ["John"]    }  ],  "gender": "male",  "birthDate": "1974-12-25"} 

  In this example, the resourceType is ‘Patient’, indicating that the resource contains information about a patient. The identifier is a unique ID assigned to the patient by the hospital system. The name, gender, and birthDate fields provide basic demographic information about the patient. The meta and text fields contain metadata and a human-readable summary of the resource, respectively. This structure ensures that FHIR messages are both machine-readable for seamless integration across different systems and human-readable for easy interpretation by healthcare professionals. Understanding this structure is key to effectively implementing and utilizing FHIR for healthcare data exchange.  

FHIR Rest API Example

Here’s an example using curl in the command line. Note the content-type header.

curl -X POST "" \ -H "Content-Type: application/fhir+json" \-d '{ "resourceType": "Patient", "id": "example-patient", "meta": { "versionId": "1", "lastUpdated": "2024-01-01T12:30:00Z" }, "text": { "status": "generated", "div": "HTML HERE" }, "identifier": [ { "system": "", "value": "P1234" } ], "name": [ { "use": "official", "family": "Doe", "given": ["John"] } ], "gender": "male", "birthDate": "1974-12-25"}'

In this example:

  • curl -X POST is used to make a POST request.
  • The URL is the endpoint to which the POST request is sent (replace with the actual URL of your FHIR server).
  • -H “Content-Type: application/fhir+json” sets the header to indicate that the request body is a FHIR JSON.
  • -d ‘{…}’ contains the data of the patient in JSON format.

Core Capabilities of FHIR

In the world of healthcare data exchange, HL7 FHIR stands out for its core capabilities that enable seamless interoperability and improved data retrieval. Let’s take a closer look at the key features that make FHIR a powerful data standard.


The FHIR API uses a RESTful approach to facilitate efficient data exchange between systems in the healthcare industry. This API allows for easy integration and seamless communication, making it straightforward for healthcare software developers to implement FHIR into their applications.


FHIR organizes data into resources, which are predefined categories of information that address common use cases. These resources serve as building blocks for data representation and exchange, enabling consistent data structures across various healthcare platforms. Examples of FHIR resources include the Patient Resource, which contains essential demographic details, and the Observation Resource, which captures clinical observations.

Data Retrieval

One of FHIR’s strengths is its ability to retrieve granular and relevant data. With FHIR, you can request specific information and receive only the data you need, improving efficiency and reducing unnecessary data transfer. This selective data retrieval enhances performance and optimizes the use of resources.

Implementation Guide

To address specific use cases, FHIR provides an Implementation Guide that offers support on how to combine and customize resources effectively. This guide assists implementers in leveraging FHIR’s flexible framework to meet their unique requirements, promoting interoperability and streamlined implementation.

Semantic Interoperability

FHIR ensures semantic interoperability by carefully managing data usage. Through code definitions and restrictions on the use of codes, FHIR establishes a shared understanding of the meaning and structure of data. This semantic consistency enhances data exchange and collaboration among different healthcare systems.

Summary Table




Facilitates RESTful data exchange between systems


Organizes data into predefined categories for common use cases

Data Retrieval

Enables granular and selective data retrieval

Implementation Guide

Offers guidance on combining and customizing resources

Semantic Interoperability

Ensures shared understanding of data usage and meaning

Advantages of FHIR for Software Developers

FHIR offers numerous advantages for software developers in the healthcare industry. By leveraging FHIR, developers can benefit from its easy implementation, wide adoption, vendor support, free tools, interoperability, and adherence to web standards. If your organization lacks the in-house expertise required to implement FHIR, consider working with a healthcare software outsourcing company and relying on their in-house knowledge. Let’s explore these advantages of FHIR in more detail:

Easy Implementation

Implementing FHIR is straightforward, with simple interfaces that can be implemented within a single day. Developers can quickly get up to speed and start leveraging the capabilities of FHIR in their applications. This ease of implementation reduces development time and allows for faster deployment of healthcare solutions.

Wide Adoption

FHIR has gained significant traction in the healthcare sector, with 24% of US healthcare stakeholders presently utilizing FHIR APIs. Major vendors, including Apple, Microsoft, Google, Epic, and Cerner, also support FHIR. This wide adoption ensures that FHIR is continuously evolving and receiving updates and enhancements to meet the industry’s evolving needs.

Vendor Support

Developers can rely on the expertise and resources offered by leading healthcare vendors to ensure the successful adoption and integration of FHIR into their applications. This support includes documentation, reference implementations, and developer communities that foster collaboration and knowledge sharing.

Free Tools

FHIR offers developers access to a variety of free tools that facilitate application development. These tools include reference servers and implementation libraries, which serve as valuable resources for understanding and implementing FHIR specifications. Additionally, developers can benefit from the numerous public examples available, providing practical guidance and inspiration for developing FHIR-based solutions.


FHIR promotes interoperability, enabling seamless data exchange between different healthcare systems and applications. Its RESTful approach and standardized data formats, such as XML and JSON, facilitate communication and integration across disparate systems. With FHIR, developers can build interoperable applications that can exchange data efficiently and improve coordination of care.

Web Standards

FHIR is built on familiar web standards like XML, JSON, HTTP, and OAuth. Leveraging these standards makes it easier for developers to work with FHIR, as they already have experience and knowledge of these technologies. This familiarity reduces the learning curve and enables developers to leverage existing tools and frameworks for FHIR implementation.

In summary, FHIR provides software developers in the healthcare industry with a range of advantages, including easy implementation, wide adoption, vendor support, free tools, and interoperability. By embracing FHIR and its adherence to web standards and technical safeguards of the HIPPA, developers can accelerate the development of healthcare applications and contribute to the advancement of healthcare interoperability.



Easy Implementation

Implementing FHIR is straightforward, with simple interfaces that can be implemented within a single day.

Wide Adoption

FHIR has gained significant traction in the healthcare industry, with major vendors supporting its adoption.

Vendor Support

Leading healthcare vendors provide support for FHIR implementations, including documentation and reference implementations.

Free Tools

FHIR offers access to a variety of free tools, such as reference servers and implementation libraries.


FHIR enables seamless data exchange and improved coordination of care through standardized data formats and RESTful APIs.

Web Standards

FHIR is built on familiar web standards like XML, JSON, HTTP, and OAuth, making it easier for developers to work with.

FHIR Use Cases and Industry Adoption

FHIR, known as Fast Healthcare Interoperability Resources, has gained significant adoption among institutional healthcare providers due to its wide range of use cases. This interoperability standard has provided a consistent, easy-to-implement, and rigorous mechanism for exchanging data between healthcare applications. Let’s explore some of the key use cases and real-world applications of FHIR.

Enhancing Interoperability at UPMC

One notable example of FHIR adoption is the University of Pittsburgh Medical Center (UPMC), which implemented FHIR to enhance interoperability across its ambulatory and hospital-based electronic health record (EHR) systems. By leveraging FHIR, UPMC has been able to improve data exchange between different healthcare systems, enabling better coordination of care and streamlined information sharing.

Facilitating Genomic Data Interoperability

FHIR has also been instrumental in facilitating genomic data interoperability, an essential component in precision medicine. Projects like GenomeX have utilized FHIR to seamlessly exchange genomic data between different systems, allowing healthcare providers to access and utilize this valuable information for personalized patient care.

Improving Clinical Decision Support

FHIR has proven to be a valuable tool in improving clinical decision support systems by integrating algorithms and artificial intelligence (AI) applications. With the seamless exchange of data enabled by FHIR, healthcare providers can leverage these advanced technologies to enhance diagnostic accuracy, treatment planning, and patient outcomes.

Fostering Innovation in the Health IT Community

FHIR adoption has gained momentum through hackathons, developer programs, and connect-a-thons, where innovative ideas and solutions utilizing FHIR are identified and developed. The health IT community has embraced FHIR, recognizing its potential to drive innovation and improve healthcare delivery.

Success in Patient Data Access, Care Coordination, and Precision Medicine

The FHIR community has achieved success in various areas, including patient data access, care coordination, and precision medicine. FHIR’s standardized approach to data exchange ensures that patients have easy access to their health data, empowering them to actively participate in their healthcare decisions. Care coordination among medical providers is also enhanced through the seamless exchange of information, enabling better collaboration and continuity of care. Additionally, FHIR’s capabilities contribute to the advancement of precision medicine by enabling the integration of genomics, clinical data, and advanced analytics.

FHIR Use Cases

Industry Adoption

Enhancing interoperability at UPMC


Facilitating genomic data interoperability


Improving clinical decision support


Fostering innovation in the health IT community


Success in patient data access, care coordination, and precision medicine


The impact of FHIR on patients and providers

FHIR has the potential to significantly impact both patients and healthcare providers. By leveraging FHIR, healthcare experiences can become more seamless and accessible, resembling other internet-based experiences. This fosters easier access and sharing of personal medical data, empowering patients in their healthcare journey.

One of the key benefits of FHIR is its ability to connect electronic health records (EHRs) with patient-generated data from wearables and remote patient monitoring devices. This integration improves data accessibility for providers, offering a more comprehensive view of patients’ health status.

FHIR also enables care coordination by linking disparate systems and facilitating the integration of data into comprehensive personal health records. This holistic approach allows providers to streamline workflows and make informed decisions based on a complete picture of the patient’s health.

Furthermore, FHIR empowers providers to customize their toolsets, allowing them to access data at a granular level and leverage analytics for improved clinical decision support. This enhanced decision-making aids in delivering personalized and effective healthcare services.

Benefits of FHIR for patients and providers:

  • Simplifies access and sharing of personal health data
  • Connects EHRs with patient-generated data
  • Improves data accessibility for healthcare providers
  • Facilitates care coordination and integration of data
  • Enables customization of toolsets for providers
  • Enhances clinical decision support through analytics

The Future of FHIR and Its Role in Interoperability

FHIR has experienced significant growth and adoption in the healthcare sector. One key factor contributing to the continued relevance of FHIR is its alignment with the information blocking provisions of the 21st Century Cures Act. By supporting patient data access through third-party apps and APIs, FHIR promotes transparency and patient engagement.

FHIR is expected to play a significant role in future developments. These include advancements in healthcare IoT, population health management, and precision medicine. FHIR’s flexibility and adaptability make it particularly suited to address the evolving needs of the industry.

Table: Benefits of FHIR for Future Healthcare Developments

Future Healthcare Developments

Benefits of FHIR

Healthcare IoT

Seamless data exchange between IoT devices, EHR systems, and healthcare providers

Population Health Management

Improved data sharing and coordination for more effective population health initiatives

Precision Medicine

Enhanced interoperability to support personalized treatment plans based on individual patient data

FHIR’s wide adoption and support from industry leaders contribute to its continued relevance and impact. As more healthcare organizations and providers recognize the benefits of FHIR, its role in driving interoperability will only grow stronger.


The HL7 FHIR standard is revolutionizing the industry by transforming health data exchange and enabling seamless interoperability. With its focus on ease of implementation, wide adoption, and support from major vendors, FHIR is driving innovation and improving patient care.

FHIR allows for quick and efficient data exchange, facilitating the sharing of clinical and administrative information across different systems in the healthcare ecosystem. Its API and utilization of common internet technologies make it easy to integrate into existing infrastructures.

FHIR’s granular approach to data retrieval and customization ensures that healthcare organizations have access to information at the necessary level of detail. This promotes enhanced decision-making and care coordination and ultimately improves patient outcomes.

As the healthcare sector continues to evolve and embrace digital transformation, HL7 FHIR will contribute to advancements in healthcare IoT, population health management, and precision medicine, ushering in a new era of data-driven healthcare delivery.


How does FHIR work in the healthcare industry?

FHIR works by providing a standardized way to access and exchange healthcare information. It allows healthcare systems to communicate with each other and share patient information in a structured and secure manner.

What are FHIR resources?

FHIR resources are the building blocks of the FHIR standard. They represent different types of clinical and administrative data such as patient records, medications, observations, and procedures, among others.

What are some common terms related to HL7 FHIR?

Some common terms related to HL7 FHIR include FHIR APIs, data elements, HL7 Fast Healthcare Interoperability, healthcare apps, and the exchange of healthcare data, among others.

How does HL7 FHIR support the exchange of healthcare data?

HL7 FHIR supports the exchange of healthcare data by providing a standardized framework for representing and accessing healthcare information. It allows for the seamless and secure exchange of data between different healthcare applications and systems.

Is HL7 FHIR open source?

Yes, HL7 FHIR is an open-source standard developed by Health Level Seven International (HL7). It is freely available for use and implementation, making it accessible to a wide range of organizations and developers in the healthcare industry.

What is the role of HL7 in the implementation of FHIR?

HL7 plays a key role in the implementation of FHIR by providing guidance, support, and resources to vendors and healthcare providers looking to adopt the FHIR standard for healthcare interoperability. It oversees the development and evolution of the FHIR standard.

How does FHIR contribute to EHR-based data sharing?

FHIR contributes to EHR-based data sharing by enabling the seamless exchange of electronic health records (EHR) data between different healthcare applications and systems. It allows for the secure and standardized sharing of patient information across various healthcare settings.


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