ICD-10-CM 2027 diagnosis code
A83.0Japanese encephalitis
A83.0 is a valid, billable ICD-10-CM code for japanese encephalitis. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About A83.0
A83.0 is the ICD-10-CM diagnosis code for Japanese encephalitis. It belongs to category A83 (mosquito-borne viral encephalitis), block A80-A89 (viral and prion infections of the central nervous system) and chapter 1 (certain infectious and parasitic diseases). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within A83 (mosquito-borne viral encephalitis), A83.0 is specifically for Japanese encephalitis. Related codes cover Western equine encephalitis (A83.1), Eastern equine encephalitis (A83.2), St Louis encephalitis (A83.3), Australian encephalitis (A83.4), California encephalitis (A83.5), Rocio virus disease (A83.6), other mosquito-borne viral encephalitis (A83.8) and unspecified (A83.9).
As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 023 (Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis with MCC or Antineoplastic Implant or Epilepsy with Neurostimulator, relative weight 5.7444), DRG 024 (Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis without MCC, relative weight 3.9708), DRG 097 (Non-Bacterial Infection of Nervous System Except Viral Meningitis with MCC, relative weight 3.8226), DRG 098 (Non-Bacterial Infection of Nervous System Except Viral Meningitis with CC, relative weight 2.2706) and DRG 099 (Non-Bacterial Infection of Nervous System Except Viral Meningitis without CC/MCC, relative weight 1.5256), in MDC 01 (Diseases and Disorders of the Nervous System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 062.0 (Japanese encephalitis).
Notes that apply from higher levels
Instructions written at a parent level also apply to A83.0.
Broader instructions also apply from A80-A89 Viral and prion infections of the central nervous system and Chapter 1: Certain infectious and parasitic diseases.
Alphabetic index entries
8 entriesTerms in the official ICD-10-CM index that lead to A83.0.
- Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › Japanese (B type)
- Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › Russian › autumnal
- Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › summer
- Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › type › B
- Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › viral, virus › arthropod-borne NEC › mosquito-borne › Japanese (B type)
- Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › viral, virus › arthropod-borne NEC › mosquito-borne › type B
- Infection, infected, infective (opportunistic) › Japanese B encephalitis
- Japanese › B-type encephalitis
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 01 · Diseases and Disorders of the Nervous System
MDC 01 · Diseases and Disorders of the Nervous System
ICD-9-CM equivalent
Converter →- 062.0Japanese encephalitisexact
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about A83.0
Is A83.0 billable?
- Yes. A83.0 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A83.0 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A83.0 as a principal diagnosis.
Is A83.0 a CC or MCC?
- A83.0 is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.
What DRG does A83.0 group to?
- A83.0 is used in the MS-DRG v44.0 logic for MS-DRG 023 (Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis with MCC or Antineoplastic Implant or Epilepsy with Neurostimulator), MS-DRG 024 (Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis without MCC), MS-DRG 097 (Non-Bacterial Infection of Nervous System Except Viral Meningitis with MCC), MS-DRG 098 (Non-Bacterial Infection of Nervous System Except Viral Meningitis with CC) and MS-DRG 099 (Non-Bacterial Infection of Nervous System Except Viral Meningitis without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for A83.0?
- The CMS General Equivalence Mappings map A83.0 to ICD-9-CM 062.0.