2026 ICD-10-CM Diagnosis Code J09.X1Influenza due to identified novel influenza A virus with pneumonia

ICD-10-CM Codes›J00–J99›J09-J18›J09

ICD-10-CM J09.X1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

J09.X1 is a billable ICD-10-CM diagnosis code for influenza due to identified novel influenza A virus with pneumonia. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 193 through 195, 974 through 976. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Influenza and Pneumonia (except that caused by tuberculosis).

Code Identity

ICD-10-CM Code
J09.X1
Billable Status
Yes — Valid for Submission
Code Describes
Influenza due to identified novel influenza A virus with pneumonia
Short Description
Influenza due to ident novel influenza A virus w pneumonia
Parent Code
J09.X
Influenza due to identified novel influenza A virus

Code Classification

ChapterJ00–J99Diseases of the respiratory system
SectionJ09-J18Influenza and pneumonia
CategoryJ09Influenza due to certain identified influenza viruses
This CodeJ09.X1Influenza due to identified novel influenza A virus with pneumonia

Tabular List NotesGuidance

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

Code Also

  • , if applicable, associated:
  • lung abscess J85.1
  • other specified type of pneumonia

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.

    • Influenza(bronchial) (epidemic) (respiratory (upper)) (unidentified influenza virus)
      • due to
        • identified novel influenza A virus
          • with
            • pneumonia

Clinical ClassificationClinical

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

CCSR RSP003
Influenza
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR RSP002
Pneumonia (except that caused by tuberculosis)
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Flu

The flu, also called influenza, is a respiratory infection caused by viruses. Each year, millions of Americans get sick with the flu. Sometimes it causes mild illness. But it can also be serious or even deadly, especially for people over 65, newborn babies, and people with certain chronic illnesses.

The full article covers:

  • What is the flu?
  • What causes the flu?
  • What are the symptoms of the flu?
  • What other problems can the flu cause?
  • How is the flu diagnosed?
  • What are the treatments for the flu?
  • Can the flu be prevented?

Read the full article at MedlinePlus

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

Convert J09.X1 to ICD-9-CMHistory

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

ICD-9-CM
488.01 Flu dt iden avian w pneu
Approximate The match is approximate rather than exact.
ICD-9-CM
488.81 Flu dt nvl A vrs w pneu
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 J09.X1Overview

Is J09.X1 (Influenza due to identified novel influenza A virus) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report influenza due to identified novel influenza A virus with pneumonia on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does J09.X1 group to?

When influenza due to identified novel influenza A virus with pneumonia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 193, 194, 195, 974, 975, 976, with relative weights from 0.6285 to 2.8860 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of J09.X1?

Under the General Equivalence Mappings, influenza due to identified novel influenza A virus with pneumonia converts to ICD-9-CM 488.01 (flu dt iden avian w pneu) and 488.81 (flu dt nvl A vrs w pneu). 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.