The FHIR vendor ecosystem in 2026 has consolidated into distinct categories. Understanding what each does (and doesn't) helps buyers avoid category confusion.
Category 1: FHIR servers
HAPI FHIR, Aidbox, Medplum, Microsoft FHIR Server, Firely Server. Store + serve FHIR resources.
Category 2: Terminology servers
Ontoserver, HAPI Terminology, Aidbox Terminology. $expand, $validate-code, $translate.
Category 3: Integration engines
Rhapsody, Mirth Connect, InterSystems IRIS for Health. HL7v2-to-FHIR conversion, message routing.
Category 4: SDC form builders
LHC-Forms, Aidbox Formbox, Smile CDR SDC. Questionnaire authoring + rendering.
Category 5: MPI (identity resolution)
Verato, NextGate MatchMetrix, Aidbox MDM. Record linkage across sources.
Category 6: Conformance testing
Inferno, MITRE cqf-ruler. Verify implementations against IGs.
Category 7: SMART/CDS Hooks tooling
SMART auth servers, CDS Hooks sandboxes. Integration surface tooling.
Category confusion pitfalls
1. Buying a FHIR server expecting integration engine capabilities — different problem spaces. 2. Buying an integration engine expecting FHIR-native storage — engines route, they don't store canonically. 3. Rolling MPI into FHIR server selection — MPI is often a separate subsystem. 4. Skipping terminology server as "the FHIR server handles it" — most FHIR servers only have basic terminology.
The FHIR ecosystem is mature enough in 2026 that most needs have a specific vendor category. Match your problem to the right category before evaluating vendors.