Technical / Interoperability
HL7 vs FHIR: What They Mean for Healthcare Data
HL7 v2 is a long-standing messaging standard for exchanging clinical and administrative data between healthcare systems; FHIR is HL7's modern, web-API-based standard using REST and JSON. FHIR is easier to build on and is driving newer interoperability, including prior authorization.
If you work near healthcare integrations, you hear HL7 and FHIR constantly. They are related but very different, and the shift toward FHIR is changing how systems (including RCM automation) connect to EHRs and payers.
HL7 v2: the workhorse
HL7 version 2 is a decades-old messaging standard that most hospitals still run for things like admissions, orders, and results. It uses pipe-and-hat delimited messages that are efficient but not easy for modern developers to work with, and implementations vary between systems.
FHIR: the modern API standard
FHIR (Fast Healthcare Interoperability Resources) is HL7's newer standard, built on modern web technology: RESTful APIs, JSON, and discrete resources like Patient, Coverage, and Claim. It is far easier to build on, which is why regulators and vendors are pushing it.
How they compare
HL7 v2 is messaging (a system pushes a message when an event happens); FHIR is API-based (a system requests exactly the resource it needs). FHIR is more granular, developer-friendly, and web-native, while HL7 v2 remains deeply embedded in existing hospital workflows.
Why it matters for RCM
FHIR is enabling newer revenue-cycle interoperability, including electronic prior authorization (the Da Vinci PAS work). As payers and EHRs expose FHIR APIs, RCM automation can read coverage, submit authorizations, and check status through standard interfaces rather than portal scraping.
How MedXFlow AI agents handle this
MedXFlow's AI agents read and write through the interfaces your systems expose - EDI, FHIR and other APIs, and payer portals - so the revenue cycle runs across Epic, athenahealth and eClinicalWorks without a rip-and-replace.
Related resources
Frequently asked questions
Is FHIR replacing HL7 v2?
Not entirely, and not quickly. FHIR is the direction for new interoperability, but HL7 v2 is deeply embedded in existing hospital systems and will run alongside FHIR for years.
Why does FHIR matter for the revenue cycle?
FHIR APIs let systems exchange coverage, claims and authorization data in a standard, developer-friendly way, which underpins newer electronic prior authorization and eligibility interoperability.