openEHR vs. FHIR: When to Use Each

For health-system leaders, the most important thing to understand about openEHR and HL7 FHIR is that they are not rivals competing for the same job — they solve different problems and are strongest when deployed together. HL7 FHIR is an interoperability standard for exchanging healthcare information; the specification defines four exchange paradigms — a REST interface, Documents, Messages, and Services [1]. openEHR, by contrast, is a specification for storing complete, longitudinal clinical records in a vendor-neutral clinical data repository that preserves clinical meaning over decades [2]. In short: FHIR is built for data exchange, openEHR for vendor-neutral persistence. Framing them as "either/or" is the single most common — and most costly — mistake we see in health data strategy decisions.

Market Backing and Global Traction

Both standards carry serious institutional momentum, but of different kinds. FHIR's backing in the United States is regulatory. openEHR's traction is concentrated in national and regional clinical-record infrastructure programs that prioritize long-term data quality and modeling independence.

• FHIR is a U.S. regulatory mandate: Under CMS-0057-F, the CMS Interoperability and Prior Authorization Final Rule (released by the Centers for Medicare & Medicaid Services on January 17, 2024), federally regulated payers — Medicare Advantage organizations, state Medicaid and CHIP fee-for-service programs, Medicaid managed care plans, CHIP managed care entities, and Qualified Health Plan issuers on the Federally Facilitated Exchanges — must implement HL7 FHIR R4-based APIs (Patient Access, Provider Access, Payer-to-Payer, Prior Authorization, and Provider Directory), with API development and enhancement requirements generally effective January 1, 2027 [3]. This is a payer mandate; it is not a requirement across commercial insurance networks generally, which are not currently in scope.
• FHIR is widely enabled in patient-facing app ecosystems: According to ASTP/ONC Data Brief No. 79 (August 2025), in 2024, 81% of U.S. non-federal acute-care hospitals enabled patient access using apps configured to meet application programming interface specifications, and 70% enabled access using apps configured to meet HL7 FHIR specifications. These figures measure a capability that hospitals have enabled — not confirmed active daily use — and lower-resourced small, rural, Critical Access, and independent hospitals lagged in adoption [4].
• openEHR anchors national and regional clinical repositories: Several government-led programs have publicly adopted openEHR as the persistence layer for their longitudinal records. Scotland's National Digital Platform, delivered by NHS Education for Scotland, uses "a 'clinical data repository' (CDR) … that implements the openEHR standard" [5]. Digital Health and Care Wales selected an openEHR data platform, following an 18-month review, to form a "constituent part" of its national architecture. Catalonia's Catalan Health Service (CatSalut) has based its region-wide electronic health record on openEHR. Industry surveys reinforce the pattern — Black Book Research's 2025 report assessed openEHR "readiness" across 30 countries — though such vendor- and survey-derived figures (for example, headline claims of 98% population coverage in Slovenia or 8 million residents in Catalonia) should be treated as industry-survey estimates rather than audited facts. In our experience advising on these architectures, public health authorities gravitate to openEHR precisely because it protects long-term data quality and keeps clinical modeling independent of any single vendor.

The Hybrid Architecture: Coexistence, Not Competition

The mature design pattern is to use each standard for what it does best inside one coherent architecture. A recognized architectural pattern is the FHIR Facade, in which an openEHR CDR acts as the internal single source of truth and a translation layer maps openEHR Compositions to FHIR resources (for example, an openEHR blood-pressure observation to a FHIR Observation) exposed via FHIR REST APIs. Recent open research — the FHIRconnect open-source mapping language and transformation engine — demonstrates this concept concretely, mapping 24 international archetypes to 15 FHIR profiles across seven clinical domains, and establishing a reusable basis for translating between openEHR persistence and FHIR exchange [6]. Scotland's national digital ReSPECT emergency care plan is a real-world example of a production openEHR CDR at national scale: deployed in 2020, by July 2025 it had onboarded 8 of 14 health boards with more than 5,500 patients, storing structured clinical data in an openEHR clinical data repository on Scotland's National Digital Platform [5].

The Governance Mandate for Health System Leaders

The strategic decision is not which standard "wins" but which standard governs which layer of your estate. Leaders should establish, in writing, that openEHR (or an equally open persistence standard) governs the authoritative, lifelong clinical record, while FHIR governs transactional exchange with the outside world. This separation is what future-proofs the organization: applications can be replaced, vendors can be swapped, and exchange standards can evolve, all while the underlying clinical truth remains consistent and computable. Note that U.S. federal interoperability regulation reflects this same division of labor — CMS mandates FHIR APIs for the exchange and access of data, while the Office of the National Coordinator for Health Information Technology (ONC) governs the certification criteria and standards those systems are built against. Neither mandate dictates how the authoritative record is persisted internally; that is a strategic choice left to the organization. Critically, procurement must protect data portability. Every major contract should require demonstrable adherence to open standards for data persistence — not merely a FHIR API bolted on top of a proprietary database, which delivers exchange while leaving the underlying asset locked in. In our experience, the health systems that avoid vendor lock-in are those that made open, vendor-neutral persistence a hard procurement requirement rather than an afterthought.

Where CaboLabs Fits

CaboLabs (cabolabs.com) provides healthcare interoperability consulting across openEHR, FHIR, and HL7, helping executives cut through the noise and make defensible health data strategy decisions. We also build Atomik (atomik.app), an openEHR-native clinical data repository designed to serve as the vendor-neutral persistence layer of exactly this hybrid architecture — the durable internal single source of truth beneath your FHIR APIs. If your organization is weighing standards selection, planning a migration away from siloed or proprietary data, or designing a future-proof clinical data platform, talk to CaboLabs. We will help you decide what to store in openEHR, what to exchange in FHIR, and how to protect your clinical data as a long-term strategic asset rather than a vendor's liability.