This value set includes codes based on the following rules:

• Include these codes as defined in urn:oid:2.16.840.1.114222.4.5.274 version 20200526

  Code	Display
  PHC67	Born outside of U.S.
  PHC82	Lab evidence of previous disease
  PHC83	MD diagnosis of previous disease
  PHC91	Never offered vaccine
  PHC94	Parent/Patient forgot to vaccinate
  PHC95	Parent/Patient refusal
  PHC93	Parent/Patient report of disease
  PHC92	Philosophical objection
  PHC96	Religious exemption
  PHC81	Under age for vaccination

• Include these codes as defined in http://snomed.info/sct version http://snomed.info/sct/731000124108/version/20200901

  Code	Display
  397745006	Medical contraindication

• Include these codes as defined in http://terminology.hl7.org/CodeSystem/v3-NullFlavor version 20090501

  Code	Display
  OTH	Other
  UNK	Unknown