Healthcare technology leaders are witnessing a major shift away from legacy interoperability models, replacing decades of complex and costly HL7 integration protocols with more efficient, web-native solutions. RESTful APIs, particularly those based on Fast Healthcare Interoperability Resources (FHIR) standards, are transforming clinical and administrative data exchange by enabling faster development, lower costs, and greater scalability. 

While many organizations have long struggled with the technical and financial overhead of HL7 integrations, REST APIs provide a simplified and modernized framework for healthcare interoperability. FHIR alone supports approximately 80% of interoperability use cases through its core specification.  The remaining 20% are addressed through standardized implementation guides and extensions without introducing fragmentation.

Today, REST APIs power data exchange for the majority of U.S. healthcare organizations, leveraging standards-based web technologies that integrate seamlessly with existing infrastructure and development teams.

Why Healthcare Organizations Are Abandoning HL7 for REST APIs

Healthcare interoperability has undergone significant transformation over the past decades, evolving from proprietary messaging systems to standardized protocols that enable seamless data exchange across diverse healthcare ecosystems.

Traditional HL7 Standards: The Early Foundation of Interoperability

Health Level Seven International has served as the cornerstone of healthcare interoperability for decades, providing standardized messaging protocols that enable different healthcare systems to communicate effectively.

Overview of HL7 Standards

Health Level Seven (HL7) standards provide comprehensive frameworks for healthcare data exchange, supporting everything from simple administrative updates to complex clinical document transfers. HL7 V2 remains widely adopted for its flexibility and broad vendor support, while HL7 V3 introduced more structured approaches to healthcare messaging. The Clinical Document Architecture (CDA) component offers standardized formats for clinical documents, enabling consistent representation of patient information across different systems.

Limitations of Early HL7 Versions

Traditional HL7 implementations often encounter significant complexity and cost overruns due to the specialized expertise required for successful deployment. The "non-standard standard" nature of many HL7 implementations means that healthcare organizations must invest heavily in custom development work to bridge differences between vendor interpretations. Legacy platforms also struggle with the technical complexity of HL7 interfaces, leading to ongoing maintenance challenges and potential points of failure.

REST APIs in Healthcare: A Streamlined, Web-Based Approach

Representational State Transfer (REST) APIs have emerged as a modern alternative to traditional healthcare messaging protocols, leveraging contemporary web technologies and development practices to simplify system connectivity.

What are REST APIs?

REST APIs utilize standard HTTP protocols and web technologies to enable real-time data exchange between healthcare systems. This approach uses familiar tools and methods, potentially reducing the specialized knowledge requirements that drive up traditional integration costs. RESTful web services provide standardized methods for accessing and manipulating healthcare data, enabling more straightforward integration with modern applications.

Benefits of Using REST APIs in Healthcare

REST APIs offer healthcare organizations significant advantages in terms of development speed, maintenance simplicity, and scalability compared to traditional integration approaches. By leveraging existing development expertise and modern tools, healthcare organizations can accelerate implementation timelines and reduce costs. REST APIs also support broader use cases across mobile applications, patient portals, and clinical decision support systems, enabling greater flexibility and interoperability across platforms.

FHIR Implementation Guide: Making the Switch

The emergence of FHIR represents a transformative step forward in healthcare data exchange combining the semantic richness of HL7 standards with the simplicity and flexibility of modern web technologies.

Key Features of FHIR

FHIR provides a comprehensive framework for healthcare data exchange that leverages RESTful APIs and modern web technologies to simplify integration processes. According to the latest FHIR version (R4), the FHIR community has defined more than 150 resources to date, covering everything from patient demographics and clinical documents to billing systems and laboratory information. FHIR resources provide standardized representations of healthcare concepts that can be easily understood and implemented by software developers.

Advantages of FHIR Over Traditional HL7

FHIR addresses many of the fundamental challenges that have plagued traditional HL7 implementations, including complexity, vendor-specific interpretations, and limited support for modern web technologies. The RESTful architecture of FHIR enables more straightforward integration with modern applications, mobile health apps, and cloud-based services. The SMART on FHIR framework supports the development of healthcare applications that function across multiple EHR systems without requiring custom integration work for each vendor.

REST APIs and Their Role in Modern Healthcare Infrastructure

REST APIs have become the foundation for modern healthcare interoperability, enabling seamless integration between diverse systems while supporting emerging technologies such as artificial intelligence, machine learning, and connected devices.

Enhancing Real-Time Healthcare Data Exchange

RESTful APIs enable real-time data exchange capabilities that support immediate access to critical patient information across healthcare systems. This real-time capability is essential for emergency care scenarios, care coordination, and clinical decision support applications that require timely access to comprehensive health records. The low-latency characteristics of REST API implementations ensure that healthcare providers can access lab results, patient records, and medical information when they need it.

Promoting Simplicity and Faster Implementation

The adoption of REST APIs in healthcare promotes greater usability and simplified implementation compared to traditional HL7 approaches. Software development teams can leverage existing web development expertise and tools, reducing the learning curve and specialized training requirements associated with healthcare integration projects. API integrations support more agile development methodologies that enable healthcare organizations to implement and test new functionality incrementally.

Enabling Integration with Emerging Technologies

REST APIs provide the foundation for integrating emerging technologies such as artificial intelligence, machine learning, and natural language processing (NLP) into healthcare workflows. These technologies require flexible, scalable integration platforms that can handle diverse data types and processing requirements. RESTful architecture also supports smoother integration of connected medical devices, mobile health apps, and patient engagement platforms, helping organizations modernize their tech stack without the overhead of legacy systems.

REST APIs and FHIR in Healthcare Data Management

The combination of REST APIs and FHIR standards creates a powerful platform for healthcare data management addressing many of the challenges associated with traditional healthcare IT architectures.

Simplifying Implementation and Scaling

FHIR implementation provides healthcare organizations with access to modern integration capabilities that support both current operational requirements and future scalability needs. The RESTful architecture of FHIR reduces the complexity associated with traditional HL7 implementations while providing comprehensive support for healthcare workflows and clinical data exchange. Healthcare organizations can implement FHIR-based solutions incrementally, reducing project risks while enabling rapid deployment of new capabilities.

Ensuring Compliance with Privacy and Security Standards

REST APIs and FHIR implementations must address stringent privacy and security requirements that govern the handling of protected health information throughout the integration lifecycle. Modern FHIR implementations incorporate comprehensive security features, including OAuth 2.0 authentication, role-based access controls, and end-to-end encryption to ensure patient data remains protected. The 21st Century Cures Act has established new requirements for healthcare data sharing and patient access that directly impact integration architecture decisions.

Supporting IoT and AI Integration in Healthcare

The modular architecture of REST APIs and FHIR enables seamless integration with Internet of Medical Things (IoMT) devices, artificial intelligence platforms, and machine learning applications that are transforming healthcare delivery. This flexibility enables healthcare organizations to leverage emerging technologies without requiring extensive modifications to their core integration infrastructure.

Global Impact on Healthcare Delivery

The adoption of REST APIs and FHIR standards is creating a global transformation in healthcare delivery that extends beyond individual organizations to encompass entire healthcare ecosystems.

Enhancing Connectivity Worldwide

REST APIs enable healthcare organizations to participate in global health initiatives and cross-border care coordination efforts that improve patient outcomes while reducing costs. The standardized nature of FHIR enables healthcare organizations in different countries and regions to share patient information and clinical data more effectively.

Enabling Innovation Through Developer Access

The accessibility of REST APIs and FHIR standards has created a diverse community of developers and healthcare technology innovators who are building solutions that address specific healthcare challenges. Healthcare software development becomes more accessible when developers can leverage familiar web technologies and standard development tools.

Improving Care Coordination and Clinical Collaboration

The comprehensive interoperability enabled by REST APIs and FHIR standards creates new opportunities for patient care coordination and provider collaboration that improve clinical outcomes while reducing costs. Healthcare providers can access comprehensive patient information from multiple sources, enabling more informed clinical decision-making and reducing duplicate testing and procedures.

Challenges and Considerations

While REST APIs and FHIR offer significant advantages over traditional HL7 approaches, healthcare organizations must address several challenges to ensure successful implementation.

Protecting Patient Data and Ensuring Privacy 

Healthcare organizations implementing REST API-based solutions must ensure comprehensive protection of patient data throughout the integration lifecycle. This includes implementing appropriate authentication and authorization mechanisms, ensuring data encryption in transit and at rest, and maintaining comprehensive audit trails for all data access and modifications.

Integrating with Legacy Systems

Many healthcare organizations operate legacy systems that were not designed to support modern REST API-based integration approaches. These systems may require significant modifications or replacement to achieve full compatibility with FHIR-based interoperability initiatives. The integration of legacy systems with modern REST API-based platforms may require specialized middleware or integration frameworks.

Training and Adaptation for Staff Adoption

The transition from traditional HL7-based systems to REST API and FHIR-based platforms requires healthcare professionals to adapt to new workflows and technologies. Healthcare organizations must invest in comprehensive training and change management programs that ensure adoption while preserving operational efficiency and patient safety.

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Embracing REST APIs for Scalable, Modern Interoperability

For healthcare organizations seeking to transition from traditional HL7 implementations to modern REST API and FHIR-based solutions, ENTER's comprehensive RCM platform demonstrates how modern integration approaches can reduce complexity and costs while improving operational efficiency. Additionally, understanding how contract compliance management software integrates with REST API-based platforms can help organizations achieve comprehensive interoperability.

Frequently Asked Questions

What is replacing HL7?

Fast Healthcare Interoperability Resources (FHIR) is emerging as the modern successor to traditional HL7 standards. It combines the semantic richness of HL7 with RESTful web technologies, making healthcare data exchange more accessible, scalable, and developer-friendly. While FHIR adoption is accelerating, full replacement of HL7 v2, v3, and CDA standards will likely take years if not decades as organizations transition at their own pace.

What is the alternative to HL7?

REST APIs—particularly those based on FHIR—are the leading alternative to legacy HL7 messaging. These modern solutions use standard web technologies and HTTP protocols to simplify healthcare data exchange, reduce integration costs, and improve implementation speed compared to traditional HL7 approaches.

What is the difference between HL7 and API?

HL7 is a set of healthcare-specific standards that define the format and structure of clinical and administrative messages. APIs are general-purpose interfaces that allow different software systems to communicate. While HL7 focuses on message content, APIs define how data is requested, transmitted, and received—often using modern protocols like REST.

What is the equivalent of HL7?

FHIR is widely considered the modern equivalent of traditional HL7 standards. It provides the same core capabilities for healthcare data exchange but does so with RESTful APIs,  modular resource formats, and contemporary web technologies designed for easier implementation and interoperability.

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How does ENTER support the shift from HL7 to REST APIs and FHIR?

ENTER’s RCM platform is built with RESTful architecture and FHIR compatibility at its core. This enables seamless interoperability with EHRs, billing platforms, and compliance systems—without the complex, costly integrations that traditional HL7 implementations require.

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