# DriversLicense

Model ID: `DriversLicense`

Patient's driver's license information.

Stored on the FHIR Patient resource as a standard ``Patient.identifier``
with v2-0203 type ``DL`` (the HL7 code for "Driver's license number"),
the per-state OID as ``system``, the license number as ``value``, and the
expiration as ``period.end``. This is the idiomatic FHIR R4 way to carry
a DL — searchable via ``_identifier`` and consistent with how MRN and the
vendor patient ids (Athena/OpenLoop/SteadyMD) are already stored.

The DL *image* is a separate ``DocumentReference`` (LOINC 71230-7) linked
back to the patient via ``subject``; these text fields are NOT on the
DocumentReference and NOT as an HC custom extension.

Type: `object`

## Fields

| Field | Type | Required | Format | Allowed values | Default | Nullable | Description |
|---|---|---:|---|---|---|---:|---|
| `expiration_date` | `string|null` | No |  |  |  | Yes | License expiration date, when known. |
| `number` | `string|null` | No |  |  |  | Yes | Driver's license number, when known. |
| `state` | `string|null` | No |  |  |  | Yes | 2-letter US state code, e.g. 'NY', 'CA'. |

## Example

None declared in canonical OpenAPI.