2026 ICD-10-CM Diagnosis Code A92.30West Nile virus infection, unspecified

ICD-10-CM CodesA00–B99A90-A99A92

ICD-10-CM A92.30
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A92.30 is a billable ICD-10-CM diagnosis code for West Nile virus infection, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 865 through 866. Coders also document this condition as asymptomatic West Nile virus infection. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Viral infection.

Code Identity

ICD-10-CM Code
A92.30
Billable Status
Yes — Valid for Submission
Code Describes
West Nile virus infection, unspecified
Short Description
West Nile virus infection, unspecified
Same as the full description in the CMS dataset.
Parent Code
West Nile virus infection

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA90-A99Arthropod-borne viral fevers and viral hemorrhagic fevers
CategoryA92Other mosquito-borne viral fevers
This CodeA92.30West Nile virus infection, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Asymptomatic West Nile virus infection
  • Disease caused by West Nile virus
  • West Nile fever without encephalitis

Tabular List NotesGuidance

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

Inclusion Terms

  • West Nile fever NOS
  • West Nile fever without complications
  • West Nile virus NOS

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)
      • West
        • Nile (viral)
    • Virus, viral
      • West Nile (fever)

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INF008
Viral infection
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

West Nile Virus

West Nile virus (WNV) is an infectious disease. It is most often spread by the bite of an infected mosquito. Most people have no symptoms, while some may develop mild symptoms. But WNV can sometimes cause serious symptoms if the virus enters your brain.

The full article covers:

  • What is West Nile Virus?
  • How does West Nile Virus spread?
  • Who is more likely to develop West Nile Virus?
  • What are the symptoms of West Nile Virus?
  • How is West Nile Virus diagnosed?
  • What are the treatments for West Nile Virus?
  • Can West Nile Virus be prevented?

Read the full article at MedlinePlus

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

Convert A92.30 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
066.40 West Nile Fever NOS
Exact Match The mapping is direct, with no qualifiers.

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 A92.30Overview

Is A92.30 (West Nile virus infection) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report West Nile virus infection, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does A92.30 group to?

When West Nile virus infection, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 865, 866, with relative weights from 0.8696 to 1.4983 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A92.30?

Under the General Equivalence Mappings, West Nile virus infection, unspecified converts to ICD-9-CM 066.40 (West Nile Fever NOS). The mapping is a direct match.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.