ICD-10-CM > A00-B99 > B00-B09 > B01 > B01.1 B01.1 Varicella encephalitis, myelitis and encephalomyelitis Non-Billable/Non-Specific Applicable To Postchickenpox encephalitis, myelitis and encephalomyelitis Codes B01.11Varicella encephalitis and encephalomyelitisB01.12Varicella myelitis