B00.4 – Herpesviral encephalitis

ICD-10-CM 2027 diagnosis code · Viral infections characterized by skin and mucous membrane lesions

Billable code

ICD-10-CM code B00.4

Code: B00.4 (claims format: B004)
Description: Herpesviral encephalitis
Billable: Yes – valid for HIPAA-covered transactions
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 1. Certain infectious and parasitic diseases (A00-B99)
Block: B00-B09 Viral infections characterized by skin and mucous membrane lesions
Parent codes: B00

Notes for B00.4

Applicable to:

Herpesviral meningoencephalitis
Simian B disease

Excludes1 (not coded here):

herpesviral encephalitis due to herpesvirus 6 and 7 (B10.01, B10.09)
non-simplex herpesviral encephalitis (B10.0-)

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

B00 – Herpesviral [herpes simplex] infections

Excludes1 (not coded here):

congenital herpesviral infections (P35.2)

Excludes2 (not included here):

anogenital herpesviral infection (A60.-)
gammaherpesviral mononucleosis (B27.0-)
herpangina (B08.5)

Index terms for B00.4

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in B00

B00.0 – Eczema herpeticumBillable
B00.1 – Herpesviral vesicular dermatitisBillable
B00.2 – Herpesviral gingivostomatitis and pharyngotonsillitisBillable
B00.3 – Herpesviral meningitisBillable
B00.5 – Herpesviral ocular diseaseHeader
B00.7 – Disseminated herpesviral diseaseBillable
B00.8 – Other forms of herpesviral infectionsHeader
B00.9 – Herpesviral infection, unspecifiedBillable

Frequently asked questions

What is ICD-10 code B00.4?

B00.4 is the ICD-10-CM code for herpesviral encephalitis, in the block B00-B09 (Viral infections characterized by skin and mucous membrane lesions).

Is B00.4 a billable code?

Yes. B00.4 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does B00.4 belong to?

It belongs to category B00 – Herpesviral [herpes simplex] infections.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.