A MyChart-shaped CapabilityStatement, dual-coded category OIDs on Observation and Encounter, a narrow Patient.Create demographics subset, and pre-resolved sandbox patient and encounter references.
Epic emits proprietary OIDs alongside the standard category coding on several resource types. A parser that assumes a single coding, or that takes coding[0], silently reads the wrong system — a failure that never appears against a generic FHIR server because no generic server does this. It is the strongest single signal that you are talking to Epic.
The demographics subset Epic accepts on create is smaller than what US Core marks must-support. Integrations that build a full US Core Patient and POST it hit rejections at the field level, not the resource level, so the error is easy to misread as a bad payload rather than a vendor constraint.
189 path-level rows mapped against US Core 6.1 with expected versus observed values, multi-patient evidence, and a source citation per row. Browse them filterably on the public Epic map page, see using the map for a walkthrough, or compare against Oracle Health (Cerner) and MEDITECH.
Compatible with Epic's published FHIR R4 CapabilityStatement. Not affiliated with or endorsed by Epic Systems Corporation; trademarks used for identification only.