ICD-10-CM 2027
ICD-10 code for panencephalitis
From the official ICD-10-CM alphabetic index entry “Panencephalitis, subacute, sclerosing”. Page updated September 29, 2026.
About coding panencephalitis
The ICD-10-CM code for panencephalitis is A81.1 (Subacute sclerosing panencephalitis).
Within A81 (atypical virus infections of central nervous system), A81.1 is specifically for subacute sclerosing panencephalitis. Related codes cover Creutzfeldt-Jakob disease (A81.0), progressive multifocal leukoencephalopathy (A81.2), other atypical virus infections of central nervous system (A81.8) and atypical virus infection of central nervous system, unspecified (A81.9).
Use an additional 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) and 1 more.
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
Common questions about panencephalitis ICD-10 codes
What is the ICD-10 code for panencephalitis?
- A81.1 — Subacute sclerosing panencephalitis.
Is A81.1 billable?
- Yes. A81.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A81.1 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A81.1 as a principal diagnosis.
Is A81.1 a CC or MCC?
- A81.1 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.