FHIR R4 Encounter resource example

Encounter is a visit: when it happened, what kind it was and who took part. Observations, Conditions and Procedures recorded during the visit can point to it through encounter.

The Encounter in JSON

{
  "resourceType": "Encounter",
  "id": "checkup",
  "status": "finished",
  "class": {
    "system": "http://terminology.hl7.org/CodeSystem/v3-ActCode",
    "code": "AMB",
    "display": "ambulatory"
  },
  "type": [
    {
      "coding": [
        {
          "system": "http://snomed.info/sct",
          "code": "185349003",
          "display": "Encounter for check up"
        }
      ]
    }
  ],
  "subject": {
    "reference": "Patient/example",
    "display": "Jane Doe"
  },
  "participant": [
    {
      "individual": {
        "reference": "Practitioner/dr-smith",
        "display": "Dr. Alex Smith"
      }
    }
  ],
  "period": {
    "start": "2026-10-01T08:15:00-05:00",
    "end": "2026-10-01T08:45:00-05:00"
  },
  "reasonCode": [
    {
      "text": "Annual check-up"
    }
  ],
  "serviceProvider": {
    "reference": "Organization/clinic",
    "display": "Springfield Family Clinic"
  }
}

Validator result: raw JSON · open the validator

informationNo errors: this Encounter matches the FHIR R4 structure checked here.

The elements that matter

Element	Cardinality	Notes
`status`	1..1	`planned`, `in-progress`, `finished` and others.
`class`	1..1	One Coding in R4 (AMB, IMP, EMER, VR for virtual…). In R5 it became an array.
`type`	0..*	The specific kind of visit.
`period`	0..1	Start and end.
`participant`	0..*	Practitioners and others who took part.

The full definition is in the FHIR R4 Encounter specification.

Common mistakes and the errors they cause

Class as an array (r5 style)

R5 changed class to 0..*; in R4 it is a single Coding.

errorEncounter.classExpected a single Coding object, not an array (in FHIR R4 this element has cardinality 0..1 or 1..1).

Status from r5

R5 renamed finished to completed; R4 rejects it.

errorEncounter.statusEncounter.status 'completed' is not in the required value set (arrived, cancelled, entered-in-error, finished, in-progress, onleave, planned, triaged, unknown).

Missing class

Encounter.class is 1..1 in R4.

errorEncounter.classRequired element is missing.

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More examples

Related guides

How to integrate clinic systems with a FHIR backendTutorial: connect a clinic EMR to patients' FHIR R4 records — directory of doctors, matching by record number, a visit as one transaction with the doctor as author, lab reports, other providers' data and webhooks.
FHIR platformHL7 FHIR R4 explained and how Anpheros implements it as a managed FHIR database: 26 resource types, search, history, transactions, $everything, the International Patient Summary and the simpler REST view of the same data.