2026 ICD-10-CM Diagnosis Code A94Unspecified arthropod-borne viral fever

ICD-10-CM Codes›A00–B99›A90-A99›A94

ICD-10-CM A94
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A94 is a billable ICD-10-CM diagnosis code for unspecified arthropod-borne viral fever. 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 arbovirus hemorrhagic fever. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Viral infection.

Code Identity

ICD-10-CM Code
A94
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified arthropod-borne viral fever
Chapter
A90-A99
Arthropod-borne viral fevers and viral hemorrhagic fevers

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA90-A99Arthropod-borne viral fevers and viral hemorrhagic fevers
CategoryA94Unspecified arthropod-borne viral fever
This CodeA94Unspecified arthropod-borne viral fever

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Arbovirus hemorrhagic fever
  • Arbovirus infection
  • Disease caused by Arthropod
  • Disease caused by Vesiculovirus
  • Isfahan fever
  • Rodent-borne hemorrhagic fever

Tabular List NotesGuidance

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

Inclusion Terms

  • Arboviral fever NOS
  • Arbovirus infection 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.

    • Disease, diseased
      • arthropod-borne NOS (viral)
    • Disease, diseased
      • viral, virus
        • arbovirus NOS
    • Disease, diseased
      • viral, virus
        • arthropod-borne NOS
    • Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)
      • arbovirus, arboviral
    • Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)
      • arbovirus, arboviral
        • hemorrhagic
    • Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)
      • hemorrhagic (arthropod-borne) NOS
    • Infection, infected, infective(opportunistic)
      • arbovirus (arbor virus)
    • Infection, infected, infective(opportunistic)
      • virus, viral NOS
        • arborvirus, arbovirus arthropod-borne

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

Viral Infections

Viruses are very tiny germs. They are made of genetic material (either DNA or RNA) inside of a protein coating. There are a huge number of viruses on earth. Only a small number of them can infect humans. Those viruses can infect our cells, which may cause disease.

The full article covers:

  • What are viruses?
  • How are viruses spread?
  • How do viruses cause disease?
  • What are the treatments for viral infections?
  • Can viral infections be prevented?

Read the full article at MedlinePlus

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

Convert A94 to ICD-9-CMHistory

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

ICD-9-CM
066.9 Arthropod virus NOS
Approximate The match is approximate rather than exact.

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 A94Overview

Is A94 (Unspecified arthropod-borne viral fever) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified arthropod-borne viral fever on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does A94 group to?

When unspecified arthropod-borne viral fever 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 A94?

Under the General Equivalence Mappings, unspecified arthropod-borne viral fever converts to ICD-9-CM 066.9 (arthropod virus NOS). The mapping is approximate, so confirm the match fits the documentation.

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.