2026 ICD-10-CM Diagnosis Code A32.9Listeriosis, unspecified

ICD-10-CM Codes›A00–B99›A30-A49›A32

ICD-10-CM A32.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A32.9 is a billable ICD-10-CM diagnosis code for listeriosis, unspecified. 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 food poisoning caused by Listeria monocytogenes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections.

Code Identity

ICD-10-CM Code
A32.9
Billable Status
Yes — Valid for Submission
Code Describes
Listeriosis, unspecified
Short Description
Listeriosis, unspecified
Same as the full description in the CMS dataset.
Parent Code
A32
Listeriosis

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA30-A49Other bacterial diseases
CategoryA32Listeriosis
This CodeA32.9Listeriosis, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Food poisoning caused by Listeria monocytogenes
  • Infection caused by Listeria
  • Invasive listeriosis
  • Listeria miscarriage
  • Listeriosis

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.

    • Listeriosis, listerellosis

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

  • Listeriosis

    infections with bacteria of the genus listeria.

  • Listeria

    a genus of bacteria which may be found in the feces of animals and man, on vegetation, and in silage. its species are parasitic on cold-blooded and warm-blooded animals, including man.

  • Invasive Listeriosis

    a bacterial infection by listeria monocytogenes in a sterile body compartment.

Patient EducationClinical

Listeria Infections

Listeriosis is a foodborne illness caused by Listeria monocytogenes, bacteria found in soil and water. It can be in a variety of raw foods as well as in processed foods and foods made from unpasteurized milk. Listeria is unlike many other germs because it can grow even in the cold temperature of the refrigerator.

Read the full article at MedlinePlus

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

Convert A32.9 to ICD-9-CMHistory

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

ICD-9-CM
027.0 Listeriosis
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 A32.9Overview

Is A32.9 (Listeriosis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report listeriosis, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does A32.9 group to?

When listeriosis, unspecified 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 A32.9?

Under the General Equivalence Mappings, listeriosis, unspecified converts to ICD-9-CM 027.0 (listeriosis). 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.