<StructureDefinition xmlns="http://hl7.org/fhir">
  <url value="https://example.org/fhir/StructureDefinition/VeteranAttributePatient" />
  <name value="VeteranAttributePatient" />
  <status value="draft" />
  <fhirVersion value="4.0.1" />
  <kind value="resource" />
  <abstract value="false" />
  <type value="Patient" />
  <baseDefinition value="http://hl7.org/fhir/us/core/StructureDefinition/us-core-patient" />
  <derivation value="constraint" />
  <differential>
    <element id="Patient.identifier">
      <path value="Patient.identifier" />
      <slicing>
        <discriminator>
          <type value="pattern" />
          <path value="$this" />
        </discriminator>
        <rules value="open" />
      </slicing>
      <short value="VA identification number" />
      <definition value="VA identification number for VA patients" />
    </element>
    <element id="Patient.identifier:vanumber">
      <path value="Patient.identifier" />
      <sliceName value="vanumber" />
      <short value="VA Indetification Number" />
      <definition value="VA indentification number for VA patients" />
      <requirements value="VA identification number is a unique identifier for interoporability" />
      <max value="1" />
      <patternIdentifier>
        <use value="usual" />
        <system value="http://va.gov/mpi" />
      </patternIdentifier>
    </element>
    <element id="Patient.identifier:medicarenumber">
      <path value="Patient.identifier" />
      <sliceName value="medicarenumber" />
      <short value="Medicare Number" />
      <definition value="Medicare identification number for Medicare patients" />
      <requirements value="Medicare identification number is a unique identifier for interoporability and is used for member match" />
      <max value="1" />
      <patternIdentifier>
        <use value="official" />
        <system value="http://hl7.org/fhir/sid/us-mbi" />
      </patternIdentifier>
    </element>
  </differential>
</StructureDefinition>