2027 ICD-10-CM Diagnosis Code A92.1O'nyong-nyong fever

ICD-10-CM Codes›A00–B99›A90-A99›A92

ICD-10-CM A92.1
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A92.1 is a billable ICD-10-CM diagnosis code for O'nyong-nyong 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 186 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Viral infection.

Code Identity

ICD-10-CM Code
A92.1
Billable Status
Yes — Valid for Submission
Code Describes
O'nyong-nyong fever
Short Description
O'nyong-nyong fever
Same as the full description in the CMS dataset.
Parent Code
A92
Other mosquito-borne viral fevers

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA90-A99Arthropod-borne viral fevers and viral hemorrhagic fevers
CategoryA92Other mosquito-borne viral fevers
This CodeA92.1O'nyong-nyong fever

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • O'nyong-nyong fever

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A92.1: its own notes plus those printed at A92 and 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

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From A92 Other mosquito-borne viral fevers applies to 11 codes
  • Ross River disease (B33.1)

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.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name A92.1, its category, or a range that includes it.

Code First 1

These codes say to code first a condition named in the note, and A92.1 is one of the conditions named.

  • M01 Direct infections of joint in infectious and parasitic diseases classified elsewhere
    O'nyong-nyong fever (A92.1)

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 A92.1 to ICD-9-CMHistory

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

ICD-9-CM
066.3 Mosquito-borne fever NEC
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 A92.1Overview

What is the ICD-10 code for O'nyong-nyong fever?

The ICD-10-CM code for O'nyong-nyong fever is A92.1 (sometimes written as A921). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is A92.1 (Other mosquito-borne viral fevers) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report O'nyong-nyong fever on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does A92.1 group to?

When O'nyong-nyong 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 A92.1 a CC or MCC?

CMS lists A92.1 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 186 closely related codes in its exclusion list.

Can A92.1 be reported with B33.1?

Not as a rule. The Excludes1 note at A92, which applies to A92.1, lists "Ross River disease (B33.1)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).