All ICD10 Codes

A86

Billable
ChapterA00–B99
Rankcategory
Description

Unspecified viral encephalitis

About ICD-10-CM code A86

The ICD-10-CM tabular list places Unspecified viral encephalitis at code A86, inside A00-B99 Certain Infectious and Parasitic Diseases, within Viral and prion infections of the central nervous system (A80-A89). You can submit this code on claims since it carries full billing specificity.

Metadata & Insights
  • •Billable/specific code (valid for reimbursement).
  • •Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99).

CH1 Parent Instructions

Includes
  • diseases generally recognized as communicable or transmissible
Excludes1(Not coded here. Use a different code.)
  • certain localized infections - see body system-related chapters
Excludes2(Not included here. Code separately if applicable.)
  • carrier or suspected carrier of infectious disease (Z22.-)
  • infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
  • infectious and parasitic diseases specific to the perinatal period (P35-P39)
  • influenza and other acute respiratory infections (J00-J22)
Use Additional Code
  • code to identify resistance to antimicrobial drugs (Z16.-)

A80-A89 Parent Instructions

Excludes1(Not coded here. Use a different code.)
  • postpolio syndrome (G14)
  • sequelae of poliomyelitis (B91)
  • sequelae of viral encephalitis (B94.1)

Instructional Notes

Includes
  • Viral encephalomyelitis NOS
  • Viral meningoencephalitis NOS

Clinical Hierarchy

BillableHas subcodes
CH1Certain infectious and parasitic diseases (A00-B99)
A80-A89Viral and prion infections of the central nervous system (A80-A89)
A86Unspecified viral encephalitisBillable

Applicable Ancestor Context

The following parent sections contain instructions or notes that apply to A86:

blockA80-A89
Viral and prion infections of the central nervous system (A80-A89)
View context instructions
chapterCH1
Certain infectious and parasitic diseases (A00-B99)
View context instructions

MS-DRG Classification

2026 v43.1

This code is grouped within the following Diagnosis Related Group(s) for clinical reimbursement:

DRG 097
Non-Bacterial Infection of Nervous System Except Viral Meningitis with MCC
DRG 098
Non-Bacterial Infection of Nervous System Except Viral Meningitis with CC
DRG 099
Non-Bacterial Infection of Nervous System Except Viral Meningitis without CC/MCC
DRG 974
HIV with Major Related Condition with MCC
DRG 975
HIV with Major Related Condition with CC
DRG 976
HIV with Major Related Condition without CC/MCC

Cross Reference

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