2026 ICD-10-CM Diagnosis Code A48.2Nonpneumonic Legionnaires' disease [Pontiac fever]

ICD-10-CM Codes›A00–B99›A30-A49›A48

ICD-10-CM A48.2
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A48.2 is a billable ICD-10-CM diagnosis code for nonpneumonic Legionnaires' disease [Pontiac fever]. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 867 through 869. Coders also document this condition as cutaneous involvement legionellosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections.

Code Identity

ICD-10-CM Code
A48.2
Billable Status
Yes — Valid for Submission
Code Describes
Nonpneumonic Legionnaires' disease [Pontiac fever]
Short Description
Nonpneumonic Legionnaires' disease [Pontiac fever]
Same as the full description in the CMS dataset.
Parent Code
A48
Other bacterial diseases, not elsewhere classified

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA30-A49Other bacterial diseases
CategoryA48Other bacterial diseases, not elsewhere classified
This CodeA48.2Nonpneumonic Legionnaires' disease [Pontiac fever]

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Cutaneous involvement legionellosis
  • Disseminated legionella infection
  • Extrapulmonary legionella infection
  • Legionella encephalopathy
  • Legionella infection
  • Pontiac fever

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
      • legionnaires'
        • nonpneumonic
    • Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)
      • Pontiac
    • Infection, infected, infective(opportunistic)
      • Legionella pneumophila
        • nonpneumonic
    • Legionellosis
      • nonpneumonic
    • Legionnaires'
      • disease
        • nonpneumonic

Clinical ClassificationClinical

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

CCSR INF003
Bacterial infections
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Pontiac Fever

    a self-limited, febrile illness without pneumonia that occurs in epidemics, and that is caused by legionella species.

Patient EducationClinical

Legionnaires' Disease

Legionnaires' disease is a serious type of pneumonia caused by Legionella bacteria. The disease got its name when a group of people at an American Legion convention became ill with this type of pneumonia.

The full article covers:

  • What is Legionnaires' Disease?
  • What causes Legionnaires' disease?
  • Who is more likely to develop Legionnaires' disease?
  • What are the symptoms of Legionnaires' disease?
  • What other problems can Legionnaires' disease cause?
  • How is Legionnaires' disease diagnosed?
  • What are the treatments for Legionnaires' disease?
  • Can Legionnaires' disease be prevented?

Read the full article at MedlinePlus

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

Convert A48.2 to ICD-9-CMHistory

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

ICD-9-CM
040.89 Bacterial diseases 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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About A48.2Overview

Is A48.2 (Other bacterial diseases, not elsewhere classified) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report nonpneumonic Legionnaires' disease [Pontiac fever] on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does A48.2 group to?

When nonpneumonic Legionnaires' disease [Pontiac fever] is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 868, 869, with relative weights from 0.7297 to 2.0932 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A48.2?

Under the General Equivalence Mappings, nonpneumonic Legionnaires' disease [Pontiac fever] converts to ICD-9-CM 040.89 (bacterial diseases NEC). 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.