Modal Epic cluster: 387 of 739 production endpoints (52%) deploy this exact CapabilityStatement shape, concentrated in CA (28), TX (19), OK (13). This cluster advertises 47 US Core 6.1 profiles in its CapabilityStatement.
A CapabilityStatement shape cluster groups production FHIR endpoints by the exact CapabilityStatement they serve at runtime. Epic publishes one reference CapabilityStatement, but production hospitals deploy several distinct shapes of it — each cluster is one of those shapes.
26d8252510918342…AllergyIntolerance · CarePlan · CareTeam · Condition · Coverage · Device · DiagnosticReport · DocumentReference · Encounter · Goal · Immunization · Location · Medication · MedicationDispense · MedicationRequest · Observation · Organization · Patient · Practitioner · PractitionerRole · Procedure · Provenance · QuestionnaireResponse · RelatedPerson · ServiceRequest · Specimen
Account · AdverseEvent · Appointment · Binary · BodyStructure · Claim · Communication · ConceptMap · Consent · Contract · DeviceRequest · DeviceUseStatement · Endpoint · EpisodeOfCare · ExplanationOfBenefit · FamilyMemberHistory · Flag · Group · ImagingStudy · ImmunizationRecommendation · List · Measure · MeasureReport · Media · MedicationAdministration · NutritionOrder · Questionnaire · RequestGroup · ResearchStudy · ResearchSubject · Substance · Task · ValueSet
CA (28) · TX (19) · OK (13) · OH (13) · NY (13) · FL (12) · IL (11) · GA (10) · IN (10) · WA (10)
Bundle.total reports the page size, not the result count, when _count is set Integrators that page with _count and trust Bundle.total for progress estimation are misled by this Epic-specific quirk — Bundle.total reflects the page contents, not the result set. Use _summary=count for accurate match counting before walking pages.
From the public Epic overlay finding sweep (2026-04-26). Full vendor overlay has 22 findings with verbatim quotes and source URLs.
This outlier cluster has too few production endpoints for us to host a dedicated mock under /v/cluster/epic-cluster-A/ today. The modal Epic cluster is the wire shape that most production deployments use — that's the right starting point for integration testing.
Compatible with Epic's published FHIR R4 CapabilityStatement (Epic February 2026 release, fetched 2026-04-26). Not affiliated with or endorsed by Epic Systems Corporation. Trademarks of Epic Systems Corporation are used for identification only. Synthetic sandbox modeled after observed Epic deployment shapes. Not affiliated with the vendor or any listed hospital. Trademarks used for identification only.