A81.8 – Other atypical virus infections of central nervous system

ICD-10-CM 2027 diagnosis code · Viral and prion infections of the central nervous system

Non-billable header

ICD-10-CM code A81.8

Code: A81.8 (claims format: A818)
Description: Other atypical virus infections of central nervous system
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 1. Certain infectious and parasitic diseases (A00-B99)
Block: A80-A89 Viral and prion infections of the central nervous system
Parent codes: A81

Billable codes under A81.8

A81.8 is a header code and cannot be used on claims. Choose the most specific code:

A81.81 – KuruBillable
A81.82 – Gerstmann-Straussler-Scheinker syndromeBillable
A81.83 – Fatal familial insomniaBillable
A81.89 – Other atypical virus infections of central nervous systemBillable

Notes inherited from parent codes

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

A81 – Atypical virus infections of central nervous system

Includes:

diseases of the central nervous system caused by prions

Use additional code:

code, if applicable, to identify:
dementia with anxiety (F02.84, F02.A4, F02.B4, F02.C4)
dementia with behavioral disturbance (F02.81-, F02.A1-, F02.B1-, F02.C1-)
dementia with mood disturbance (F02.83, F02.A3, F02.B3, F02.C3)
dementia with psychotic disturbance (F02.82, F02.A2, F02.B2, F02.C2)
dementia without behavioral disturbance (F02.80, F02.A0, F02.B0, F02.C0)
mild neurocognitive disorder due to known physiological condition (F06.7-)

Block A80-A89

Excludes1 (not coded here):

postpolio syndrome (G14)
sequelae of poliomyelitis (B91)
sequelae of viral encephalitis (B94.1)

Related codes in A81

Frequently asked questions

What is ICD-10 code A81.8?

A81.8 is the ICD-10-CM code for other atypical virus infections of central nervous system, in the block A80-A89 (Viral and prion infections of the central nervous system).

Is A81.8 a billable code?

No. A81.8 is a header code with more specific child codes; report one of the billable codes listed above.

What category does A81.8 belong to?

It belongs to category A81 – Atypical virus infections of central nervous system.

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.