FHIR R4 Immunization · US Core Immunization

This resource is produced identically for the Patient Everything and Patient Summary bundles. It is not produced for Bulk Medication History.

Stable ID

The id is derived from the patient, the administration date, and the vaccine code, plus the status when the vaccine was not given. Two administrations of the same vaccine on the same day therefore resolve to a single Immunization, while a vaccine that was declined on the same day it was also given stays a separate Immunization.

Fields

Field	Cardinality	Notes
`meta.profile`	1..1	Always set to the US Core Immunization profile URL.
`status`	1..1	`completed` when the vaccine was given, or `not-done` when it was not given (for example refused or deferred). Records entered in error do not appear.
`statusReason`	0..1	Only for `not-done`: a single coding for why the vaccine was not given, usually HL7 ActReason (for example `PATOBJ`, patient objection). Immunizations provided through the API always have one; it is omitted only when the source data has no reason.
`patient`	1..1	Reference to the Patient.
`vaccineCode`	1..1	A single coding for the vaccine, usually CVX.
`occurrenceDateTime`	1..1	The date the vaccine was administered, or for `not-done` the date it was declined or deferred.
`performer.actor`	0..1	Contained PractitionerRole built from the immunization’s provider and facility. Omitted when neither is known.

US Core requires occurrenceDateTime on every Immunization. Source immunizations with no date (the administration date, or for not-done the date it was declined or deferred) are excluded from the bundle entirely, rather than being published without one.

primarySource, lotNumber, expirationDate, site, route, doseQuantity, and encounter are not populated — the source data for immunizations carries only the vaccine, the date, whether it was given and why not, and who gave it.