2026 ICD-10-CM Diagnosis Code A85Other viral encephalitis, not elsewhere classified

ICD-10-CM Codes›A00–B99›A80-A89›A85

ICD-10-CM A85
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A85 is a non-billable ICD-10-CM category code for other viral encephalitis, not elsewhere classified, so it cannot be submitted on claims. Use a more specific code from this category instead, such as A85.0, A85.1, A85.2, and A85.8.

Code Identity

ICD-10-CM Code
A85
Billable Status
No — Non-Billable Category
Code Describes
Other viral encephalitis, not elsewhere classified
Chapter
A80-A89
Viral and prion infections of the central nervous system

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA80-A89Viral and prion infections of the central nervous system
CategoryA85Other viral encephalitis, not elsewhere classified
This CodeA85Other viral encephalitis, not elsewhere classified

Specific Coding for Other viral encephalitis, not elsewhere classifiedOverview

Non-specific codes like A85 require more characters. Use one of these billable codes instead:

  • Use A85.0 for Enteroviral encephalitis

  • Use A85.1 for Adenoviral encephalitis

  • Use A85.2 for Arthropod-borne viral encephalitis, unspecified

  • Use A85.8 for Other specified viral encephalitis

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Includes

  • specified viral encephalomyelitis NEC
  • specified viral meningoencephalitis NEC

Type 1 Excludes

  • encephalitis due to cytomegalovirus B25.8
  • encephalitis due to herpesvirus NEC B10.0
  • encephalitis due to herpesvirus herpes simplex B00.4
  • encephalitis due to measles virus B05.0
  • encephalitis due to mumps virus B26.2
  • encephalitis due to poliomyelitis virus A80
  • encephalitis due to zoster B02.0
  • lymphocytic choriomeningitis A87.2
  • myalgic encephalomyelitis G93.32

Patient EducationClinical

Encephalitis

Encephalitis is inflammation (swelling) of the brain. It can happen when an infection or medical condition that affects the brain activates your immune system. The inflammation can cause a wide range of symptoms. In extreme cases, it can lead to brain damage, stroke, or even death.

The full article covers:

  • What is encephalitis?
  • What causes encephalitis?
  • Who is more likely to get encephalitis?
  • What are the symptoms of encephalitis?
  • How is encephalitis diagnosed?
  • What are the treatments for encephalitis?
  • Can encephalitis be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About A85Overview

Is A85 (Other viral encephalitis, not elsewhere classified) a billable code?

No. This is a category header that groups the codes for other viral encephalitis, not elsewhere classified, and headers cannot be submitted on claims. Claims for other viral encephalitis, not elsewhere classified need a more specific code from this category, such as A85.0, A85.1, and A85.2.