2026 ICD-10-CM Diagnosis Code A05.9Bacterial foodborne intoxication, unspecified

ICD-10-CM Codes›A00–B99›A00-A09›A05

ICD-10-CM A05.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A05.9 is a billable ICD-10-CM diagnosis code for bacterial foodborne intoxication, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 391 through 392. Coders also document this condition as bacterial food poisoning. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Foodborne intoxications.

Code Identity

ICD-10-CM Code
A05.9
Billable Status
Yes — Valid for Submission
Code Describes
Bacterial foodborne intoxication, unspecified
Short Description
Bacterial foodborne intoxication, unspecified
Same as the full description in the CMS dataset.
Parent Code
A05
Other bacterial foodborne intoxications, not elsewhere classified

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA00-A09Intestinal infectious diseases
CategoryA05Other bacterial foodborne intoxications, not elsewhere classified
This CodeA05.9Bacterial foodborne intoxication, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bacterial food poisoning
  • Enterotoxemia
  • Food poisoning
  • Food-borne gastroenteritis
  • Infective food poisoning

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.

    • Creotoxism
    • Indigestion(acid) (bilious) (functional)
      • due to decomposed food NOS
    • Intoxication
      • foodborne
    • Intoxication
      • foodborne
        • bacterial
    • Intoxication
      • foodborne
        • due to
          • bacterium
    • Kreotoxism
    • Poisoning(acute)
      • bacterial toxins
    • Poisoning(acute)
      • epidemic, fish (noxious)
        • bacterial
    • Poisoning(acute)
      • food NEC
    • Poisoning(acute)
      • kreotoxism, food

Clinical ClassificationClinical

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

CCSR INF005
Foodborne intoxications
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Enterotoxemia

    disease caused by the liberation of exotoxins of clostridium perfringens in the intestines of sheep, goats, cattle, foals, and piglets. type b enterotoxemia in lambs is lamb dysentery; type c enterotoxemia in mature sheep produces struck, and in calves, lambs and piglets it produces hemorrhagic enterotoxemia; type d enterotoxemia in sheep and goats is pulpy-kidney disease or overeating disease.

  • Clostridium perfringens

    the most common etiologic agent of gas gangrene. it is differentiable into several distinct types based on the distribution of twelve different toxins.

Patient EducationClinical

Bacterial Infections

Bacteria are tiny organisms (living things) that have only one cell. Under a microscope, they look like balls, rods, or spirals. They can be found almost everywhere on Earth. There are lots of bacteria in and on your body. In fact, your body has about 10 times more bacteria cells than human cells.

The full article covers:

  • What are bacteria?
  • How do bacterial infections spread?
  • What are the treatments for bacterial infections?
  • Can bacterial infections be prevented?

Read the full article at MedlinePlus

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

Convert A05.9 to ICD-9-CMHistory

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

ICD-9-CM
005.9 Food poisoning NOS
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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About A05.9Overview

Is A05.9 a billable code?

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

What MS-DRG does A05.9 group to?

When bacterial foodborne intoxication, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 391, 392, with relative weights from 0.7796 to 1.2683 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A05.9?

Under the General Equivalence Mappings, bacterial foodborne intoxication, unspecified converts to ICD-9-CM 005.9 (food poisoning NOS). The mapping is a direct match.

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.