HL7 vs FHIR: Which One to Choose?

Posted in HL7

Last Updated | August 30, 2022

Overview: What Is The Difference Between HL7 VS FHIR?

Are you looking for the difference between HL7 vs FHIR? Read the guide to get the correct answer. HL7 is a set of international data-sharing standards that are meant to enhance healthcare interoperability. HL7 is a clinical messaging format that supports the secure exchange of documents and healthcare messaging between healthcare organizations. HL7 uses ASCII text-based messages to communicate between different systems, such as patient management systems, healthcare information systems, EMRs, laboratory information systems, and billing systems. On the other hand, the Fast Healthcare Interoperability Resources (FHIR) standard was released in 2014, as an alternative to HL7 v2, as an open standard that enables new apps and legacy systems to more easily exchange data than in the past. This move hopes to improve interoperability and enhance the efficiency of communication. Based on RESTful principles, FHIR aims to accelerate the implementation of HL7 and enhance interaction between legacy healthcare systems, as well as allow users to gain access to medical data from various devices.

HL7 VS FHIR Standards

HL7 and its members provide a framework that defines the exchange, integration, sharing and retrieval of electronic health information. HL7 standards define a process for how information is packaged and communicated from one party to another, as well as the language which is to be used, and the correct structure and data types required for seamless integration between systems. HL7 standards support clinical practice and the management, delivery, and evaluation of health services. Some common primary HL7 standards include Clinical Document Architecture (CDA®) Products, context management specifications, HL7 Version 2 Product Suite, and HL7 Version 3 Product Suite, while Messaging and document standards for clinical specialties and groups include Arden Syntax, HL7/ANSI standards, HL7 Consumer Mobile Health Application Functional Framework, HL7 EHR-S Functional Requirements, and hundreds of others.

FHIR® is also an interoperability standard of HL7 intended to facilitate the exchange of healthcare information between healthcare providers, patients, caregivers, payers, researchers, and anyone else involved in the healthcare ecosystem. FHIR contains two sections; a content model in the form of ‘resources’, and a specification for the exchange of these resources via RESTful interfaces as well as messaging and Documents.

FHIR is known to help researchers with the exchange of information, and its two sectors collectively ensure better resource management. However, how the FHIR system is developed can impact the information exchange between the researchers. For this reason, you must choose the vendor that conducts in-depth UX research in healthcare to ensure the information exchange is secure, optimized, and error-free.

Some common FHIR standards include HL7 Fast Healthcare Interoperability Resources Specification, HL7 FHIR® IG: Payer Coverage Decision Exchange, HL7 FHIR® Implementation Guides on Bulk Data, bidirectional services, C-CDA on FHIR, clinical decision support for immunization, coverage requirements discovery, consumer-facing real-time pharmacy benefit check, electronic case reporting, healthcare-associated infection reports, payer coverage decision exchange, consumer-directed payer data exchange, structured and unstructured data capture, unsolicited notifications, and data exchange for quality measures.

HL7 VS FHIR Protocols

Health Level Seven (HL7) facilitates the sharing of vital information between different healthcare systems. It is the seventh OSI layer protocol that defines the format and the content of the messages that must be used by applications when exchanging data with one another. Here are the different HL7 Protocols:

Event Driven Protocol

Any real-world event that triggers the need for information exchange between applications, such as when the patient is admitted to or discharged from a facility or when an order needs to be placed at the pharmacy, defines an event-level protocol. Every time an application registers a real-world event, it needs to communicate this with other systems where such information is vital.

Application to Application Protocol

This protocol relates to communication between two independent applications, instead of between client-server type applications. What is important here is the message that is being exchanged between applications, and not the role of each application.

OSI Level 7 Protocol

This protocol pertains to the exact format and content of the data exchanged between the applications and not the mode of transmission between systems. HL7 has no connection with the transmission mode between applications. In most cases, a TCP/IP connection is established to deliver a message.

Exchange Protocol

This protocol delineates how data exchange between applications will be made. How this data is stored or processed by different applications isn’t of any importance here. Even though the database structure needs to coincide with HL7 message definitions, this is not compulsory.

Standard Protocol

Before a message can be exchanged between two applications, a proprietary, non-standard link needs to be created. However, all your link-building efforts can go down the drain when you are trying to connect to a third-party system. However HL7 standard protocol lets you reuse your initial development effort.


DICOM and HL7 FHIR are complementary Standards in healthcare. While both HL7 vs FHIR provides the information model for health information, DICOM offers capabilities for storing, transmitting and processing medical images. You can think of HL7 as a transaction-based protocol, which is driven by real-world events that necessitate the need for communication. As a result of these triggers or events, information systems share information with each other. On the other hand, DICOM is a much more client-oriented protocol. For example, when we talk about DICOM, imaging equipment sends requests to an MWL server to receive a work list.


Even though FHIR supports messaging (similar to HL7 V2), it also supports multiple options for facilitating data exchange among systems. The main difference between HL7 vs FHIR lies in the fact that, unlike HL7 v2, FHIR employs RESTful web services and open web technologies, such as JSON and RDF data formats. Since most developers are acquainted with these technologies, they experience a less steep learning curve than previous standards. Not to mention, The RESTful API approach replaces point-to-point interfaces with one-to-many interfaces, thereby making it much easier to exchange data and minimize the time to onboard new data exchange partners. Another major benefit of the RESTful approach is that increases interoperability between not just electronic health record (EHR) systems, but myriad other devices and systems, such as mobile apps, mobile devices, and wearables. Folio3 Custom medical software Development Company offers Folio3 EHR/EMR integration solutions that support HL7 implementation by integrating third-party technologies and wearable devices to create smarter experiences for both doctors and patients.

Another difference between HL7 v2 and FHIR is that the former still depends on document exchange for health information exchange and data interoperability. Providers using HL7 v2 typically choose a set of data to transmit and then generate a message enveloping that data. HL7 v2 still uses the Consolidated Clinical Document format that contains a great deal of critical information, just like the static data in a PDF, it becomes quite laborious to extract the information and make it usable in any other format. This type of document exchange limits the provider from digging deep into the context of the data received. Data-level change is quite critical in many applications, which is why FHIR leverages standardized application programming interface (API) standards to transcend data reconciliation challenges. Using FHIR, Applications can be plugged into a basic EHR operating system and information can then be fed into the provider workflow automatically.

Somewhat akin to segments in HL7 v2 messages, FHIR stores and exchanges meaningful pieces of data known as “resources”. Each resource contains metadata, text, or bundled collections of information that form clinical documents. The best thing about the concept of resources is that each resource has a unique identifying tag, which helps devices and applications access required data without complicated data exchange processes.

Why Is FHIR Better Than HL7?

The whole idea behind the development of FHIR is to create a basic set of resources that, individually or in combination, can solve real-world clinical and administrative problems at a fraction of the price of existing alternatives. Like segments in an HL7 v2, each FHIR resource can be sliced into types and groups, wherein each type has a unique field structure, with either composite or primitive values. These fields are either optional or compulsory, and the resources are based on XML, Atom, JSON, HTTP, and OAuth. Although a single resource may suffice for a given use case, more often than not, resources are combined and tailored to meet use case-specific requirements.

Another reason why FHIR is better than HL7 is that it offers numerous options for exchanging data among systems. In addition to supporting the messaging format of HL7, the FHIR system leverages the RESTful API approach. This allows FHIR to improve interoperability among a wide array of systems and devices beyond electronic health record (EHR) systems.

FHIR is also promising to improve information sharing, simplify implementation, and offer better support for mobile apps. Perhaps one area where FHIR especially stands out is its ability to support vital use cases that benefit providers, payers, and patients. FHIR will also facilitate patient data sharing between clinicians to provide coordinated care to patients and enhance critical decision-making. Insurance companies can use FHIR to supplement claims data with clinical data to verify details and improve outcomes. This would also solve a lot of false insurance claims and cut down on costs. As for patients, FHIR will allow patient-led care and allow users to become more involved in their healthcare and access medical information on the go through consumer-friendly apps, on the devices of their choice.

While Current interoperability efforts, such as HL7, only operate with a single aim, which is to move data back and forth and remove data reconciliation obstacles. On the other hand, the goal of FHIR is to coordinate care plans across the boundaries of systems, with the help of mobile devices and easily accessible apps. By incorporating apps that can be plugged into the basic EHR operating system and feed information directly into the provider workflow, FHIR aims to remove many of the issues associated with document exchange.

Last but not the least, FHIR has a strong focus on implementation and offers fast easy implementation. With multiple available implementation libraries, developers can kick-start development without any delay.


You can use FHIR Converter to convert legacy data (currently HL7 v2 messages) into FHIR bundles. Converting legacy data to FHIR expands the use cases for health data and enables interoperability. Folio3 Medical app development services make it a breeze to convert HL7 v2 messages into FHIR bundles.



In essence, Clinical Document Architecture is limited to “clinical” use cases or data that deals with patients and their health conditions. This model doesn’t facilitate the exchange of content that doesn’t have any clinical relevance, such as financial information. On the other hand, HL7 FHIR documents have no limitation on their content and can have data pertaining to other aspects of healthcare, such as billing and insurance.

Similarly, in CDA, the “content” of the document is expressed using a complex model, which gives implementers the flexibility to express a clinical concept in any degree of granularity. This model poses many challenges, for instance, when it comes to representing a person’s allergies or surgery. Templates are required to support interoperability. Another issue that arises with CDA is that common clinical concept are modeled differently in different circumstances. FHIR bids adieu to all these problems since all clinical (and non-clinical) content in a message is handled by referencing existing resource definitions. This gives implementers a lot of flexibility when representing common structures.

Is FHIR an HL7? 

FHIR is a draft data standard developed and nurtured by HL7 International. FHIR combines the best features of HL7’s various versions while relying on the latest and most up-to-date web standards to solve challenges in interoperability. Folio3 hl7 integration solutions ensure the integration and interoperability of electronic health information.

How do you configure authorization/access control in the FHIR store (HL7, Fhir, Hapi, and development)?

An FHIR system will need some kind of security sub-system that administers users, user authentication, and user authorization. In Role-Based Access Control (RBAC), a user needs permissions for every object they wish to access. Permissions are grouped into roles, wherein each role characterizes the functions a user can perform. If a user’s role is granted the permission to access an object, they can readily access it. FHIR supports this form of access control since FHIR Resources are object types and events such as Create, Read, Update, Delete, and Execute are operations on those objects. You can contact a healthcare app development solution provider to configure access control on your behalf.

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