What is FHIR?

You have probably experienced this before - you’ve been to one doctor for most of your life, and then you see a specialist in another hospital or another city. Now, you have to explain your health history all over again. When was the last time you got a tetanus shot? What was the name of the last antibiotic you took?

Couldn’t this be easier? Interoperability strives to answer this question, making it simpler for hospitals to exchange patient information with each other. This is the future envisioned by most interoperability initiatives.

FHIR or Fast Healthcare Interoperability Resources(pronounced “fire”) is a health data exchange standard.

FHIR defines the secure and uniform exchange of health information between different systems. It is developed and managed by HL7 International (Health Level 7 International), a not-for-profit organization that manages standards to bridge gaps in healthcare technology. FHIR is available under a free license from HL7, which encourages wide adoption and community driven innovation.

Core components of FHIR

Resources as the smallest unit of exchange

FHIR breaks down healthcare data into components, and calls the smallest unit of exchange a ‘resource’. Patient, Encounter, Observation, Procedure and MedicationStatement are all resources. Essentially, they can be thought of as the building blocks of healthcare exchange that allow for modular design.

Profiles to localize FHIR

By design, the resources defined by the international FHIR specification need to be constrained further for local use–in a nation, organization or for a use case. FHIR Profiles are a formal way for implementers to constrain and extend the base specification of a resource. Extensions are the custom fields added to resources in Profiles.

Paradigms to define exchange

FHIR Paradigms define how resources should be exchanged and consumed by different systems. The most widely used paradigms are RESTful, Documents and Messaging:

RESTful APIs: They provide a standard way to interact with FHIR resources over HTTP. This paradigm follows REST, making it easy to implement and familiar to developers.
Documents: This allows the exchange of a collection of resources as a single unit and is useful for scenarios where a complete set of related information is transferred or stored together, e.g. a discharge summary.
Messaging: This enables event-based communication between systems and is useful when actions need to be triggered based on events, or for asynchronous communication.

• Implementation Guides to bring it all together

Implementation Guides or IGs are comprehensive documents that combine multiple FHIR components to create a practical, real world implementation for specific use cases. They provide detailed guidance on how to use FHIR resources, profiles and exchange paradigms to meet specific needs and goals.

Real world implementations of FHIR

Since its introduction, FHIR has gained enormous support worldwide. The 2025 State of FHIR survey provides a comprehensive perspective on real-world adoption, implementation and regulatory frameworks. In 2025, 82 participants were surveyed, across 52 countries. Over 70% of countries report active FHIR use for some national use cases. Additionally, over 54% expect a strong increase in adoption in the next 3 years.

Here are some examples of governments adopting FHIR as part of their health IT regulations,

In the United States, a patient-facing FHIR API is a federal requirement for EHRs as part of the Office of the National Coordinator for Health IT final rule to implement the 21st Century Cures Act.
The National Health Service (NHS) in the United Kingdom uses FHIR to make integration with APIs and services easier, with the UK Core profiles guiding consistency.
Australia has the ‘My Health Record’, a national digital health record that uses FHIR to enable secure sharing of patient information.
India’s Ayushman Bharat Digital Mission (ABDM) defines FHIR as the standard to follow for health information representation and exchange. Take a look at our ABDM case study for more information.

In the FHIR Impact Showcase, held at FHIR DevDays 2025, several real-world implementations were discussed. These go beyond proof-of-concepts and are delivering improvements in care across the world. Here are some examples,

Since 2018, the iPhone Health App allows viewing of FHIR compliant medical records depending on whether providers make them available.
A collaborative note-taking feature in Epic called Happy Together Notes is enabled with FHIR’s DocumentReference resource and is live in 350+ health systems worldwide.
Patient equity analytics in the United States as part of a collaborative project between Verto Inc and Telluride Regional Medical Center is revealing care disparities. Here, FHIR serves as the underlying data model.
Beda EMR is an open-source FHIR-native, modular EMR, enabling digital transformation in research centers, clinics and hospitals.

There are also some popular accelerators and incubators for FHIR applications including,

The Argonaut Project, is a joint project of major US EHR vendors to advance industry adoption of modern, open, interoperability standards. In collaboration with other FHIR initiatives like SMART on FHIR, they create open industry Implementation Guides for high priority use cases for provider-patient and provider-provider interactions. Apple uses the Argonaut Implementation Guide.
The Da Vinci Project is an HL7 Accelerator that tackles challenges in the Value Based Care space through the implementation of FHIR, i.e. in payer-provider interactions.
Sparked is Australia’s national FHIR Accelerator focused on building a national framework for FHIR adoption with AU Core, and enabling consistency, capability and community.

Benefits of FHIR

Driving this momentous growth of FHIR all over the world are the many benefits it provides.

FHIR has a great community of experts and practitioners engaged in finding solutions to complex problems
FHIR facilitates interoperability with legacy standards such as HL7 v2 and CCD
FHIR has a REST API framework that is built using existing web standards, making it developer friendly and easy to use
FHIR is flexible and modular in design, leading to low development cost and faster development timelines

Challenges with FHIR

Implementing FHIR is not without its challenges. Here are some common challenges,

FHIR doesn’t fully solve the challenge of inconsistent clinical data as it allows for flexible implementation unless governed by Implementation Guides (IGs).
Versions DSTU2, R3, R4, R4B and R5 coexist in production and there are breaking changes between versions that necessitate significant effort in mapping and testing. As revealed in the 2025 State of FHIR survey, multiple versions are currently in use across organizations and countries.
Implementing FHIR requires significant upfront investments in terms of time, money and people

The future potential of FHIR extends globally as adoption gains traction. With increased adoption, we will see more opportunities for integration, modular applications for EHRs and increased patient control over their healthcare data.