Identifiers

Identifiers are business-level IDs that appear in Blue Button responses. Identifiers are different from FHIR resource IDs. FHIR IDs are internal system IDs. In contrast, identifiers show real-world numbers, like the Medicare Beneficiary ID found on a Medicare card.

How identifiers work

An identifier in FHIR includes a system (which identifier scheme it belongs to) and a value:

{
  "identifier": [
    {
      "system": "http://hl7.org/fhir/sid/us-mbi",
      "value": "1S00-E00-AA00"
    }
  ]
}

The system URI tells you what kind of identifier you’re looking at. The value is the actual ID.

Read more about identifiers from HL7.

Medicare Beneficiary ID (MBI)

The MBI is the primary identifier for Medicare enrollees: it’s the number on their Medicare card. In Blue Button responses, the MBI appears in the Patient resource’s identifier array with the system http://hl7.org/fhir/sid/us-mbi.

A patient may have multiple MBIs (current and historic). Use the identifier-currency extension to determine which is current. See fetching patient data for details and code examples.

MBI data is sourced from CMS’s Integrated Data Repository (IDR).