2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A94 is a billable ICD-10-CM diagnosis code for unspecified arthropod-borne viral fever. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 865 through 866. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 23 closely related codes. 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
Short Description
Unspecified arthropod-borne viral fever
Same as the full description in the CMS dataset.
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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A94: its own notes plus those printed at Chapter 1. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • diseases generally recognized as communicable or transmissible

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Arboviral fever NOS
  • Arbovirus infection NOS

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • carrier or suspected carrier of infectious disease (Z22.-)
  • certain localized infections - see body system-related chapters
  • 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

Add a second code, after this one, to fully describe the condition.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • code to identify resistance to antimicrobial drugs (Z16.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About A94Overview

What is the ICD-10 code for unspecified arthropod-borne viral fever?

The ICD-10-CM code for unspecified arthropod-borne viral fever is A94. It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

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 866, 865, with relative weights from 0.8691 to 1.3153 depending on complications. Higher weights mean higher Medicare reimbursement.

Is A94 a CC or MCC?

CMS lists A94 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 23 closely related codes in its exclusion list.

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.