2027 ICD-10-CM Diagnosis Code A90Dengue fever [classical dengue]

ICD-10-CM Codes›A00–B99›A90-A99›A90

ICD-10-CM A90
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A90 is a billable ICD-10-CM diagnosis code for dengue fever [classical dengue]. 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 1 closely related codes. Coders also document this condition as dengue. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Viral infection.

Code Identity

ICD-10-CM Code
A90
Billable Status
Yes — Valid for Submission
Code Describes
Dengue fever [classical dengue]
Short Description
Dengue fever [classical dengue]
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
CategoryA90Dengue fever [classical dengue]
This CodeA90Dengue fever [classical dengue]

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Dengue
  • Dengue virus encephalitis
  • Dengue with warning signs
  • Dengue without warning signs
  • Myelitis caused by Dengue virus

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A90: 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

Excludes1

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

  • dengue hemorrhagic fever (A91)

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

Clinical InformationClinical

  • Dengue

    an acute febrile disease transmitted by the bite of aedes mosquitoes infected with dengue virus. it is self-limiting and characterized by fever, myalgia, headache, and rash. severe dengue is a more virulent form of dengue.

Patient EducationClinical

Dengue

Dengue is a viral infection. It can be caused by four related viruses. You can get it if an infected mosquito bites you. It is common in warm, wet areas of the world. Although rare, it can be found in some parts of the United States. Outbreaks are more common during rainy seasons.

The full article covers:

  • What is dengue?
  • How does dengue spread?
  • What are the symptoms of dengue and severe dengue?
  • How is dengue diagnosed?
  • What are the treatments for dengue?
  • Can dengue be prevented?

Read the full article at MedlinePlus

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

Convert A90 to ICD-9-CMHistory

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

ICD-9-CM
061 Dengue
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About A90Overview

What is the ICD-10 code for dengue fever [classical dengue]?

The ICD-10-CM code for dengue fever [classical dengue] is A90. It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is A90 (Dengue fever [classical dengue]) a billable code?

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

What MS-DRG does A90 group to?

When dengue fever [classical dengue] 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 A90 a CC or MCC?

CMS lists A90 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 1 closely related codes in its exclusion list.

Can A90 be reported with A91?

Not as a rule. The Excludes1 note on A90 lists "dengue hemorrhagic fever (A91)". 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).