2026 ICD-10-CM Diagnosis Code A04.8Other specified bacterial intestinal infections

ICD-10-CM Codes›A00–B99›A00-A09›A04

ICD-10-CM A04.8
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A04.8 is a billable ICD-10-CM diagnosis code for other specified bacterial intestinal infections. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 371 through 373. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Intestinal infection.

Code Identity

ICD-10-CM Code
A04.8
Billable Status
Yes — Valid for Submission
Code Describes
Other specified bacterial intestinal infections
Short Description
Other specified bacterial intestinal infections
Same as the full description in the CMS dataset.
Parent Code
A04
Other bacterial intestinal infections

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA00-A09Intestinal infectious diseases
CategoryA04Other bacterial intestinal infections
This CodeA04.8Other specified bacterial intestinal infections

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bacterial infection caused by Morganella morganii
  • Bacterial infection caused by Proteus mirabilis
  • Chlamydial colitis
  • Chronic gastritis caused by Helicobacter heilmannii
  • Colitis caused by Brachyspira pilosicoli
  • Colitis caused by Chlamydia trachomatis
  • Colitis caused by Helicobacter
  • Colitis caused by Salmonella
  • Diarrhea caused by staphylococcus toxin
  • Enterobacterial enteritis of intestine
  • Enterobacterial enteritis of small intestine
  • Gastritis caused by Helicobacter
  • Gastroenteritis caused by Aeromonas
  • Gastroenteritis caused by Aeromonas hydrophila
  • Gastroenteritis caused by Aeromonas veronii
  • Gastrointestinal infection caused by Klebsiella aerogenes
  • Gastrointestinal infection caused by non-tuberculous Mycobacterium
  • Helicobacter heilmannii gastritis
  • Helicobacter pylori gastrointestinal tract infection
  • Infection caused by Enterobacter
  • Infection caused by Helicobacter pylori
  • Infection caused by Klebsiella aerogenes
  • Infection caused by Plesiomonas shigelloides
  • Infection of colon caused by Haemophilus ducreyi
  • Infection of colon caused by Spirochaetes
  • Infection of intestine caused by Vibrio
  • Intestinal Chlamydia trachomatis infection
  • Intestinal infection caused by Aeromonas hydrophila
  • Intestinal infection caused by Klebsiella aerogenes
  • Intestinal infection caused by Morganella morganii
  • Intestinal infection caused by Plesiomonas shigelloides
  • Intestinal infection caused by Proteus mirabilis
  • Intestinal infection caused by Pseudomonas
  • Intestinal infectious disease caused by anaerobic bacteria
  • Intestinal infectious disease caused by Gram-negative bacteria
  • Klebsiella oxytoca colitis
  • Methicillin resistant Staphylococcus aureus infection
  • Methicillin-resistant Staphylococcus aureus colitis
  • Methicillin-resistant Staphylococcus aureus enteritis of intestine
  • Methicillin-resistant Staphylococcus aureus enteritis of small intestine
  • Morganella infection
  • Morganella morganii gastrointestinal tract infection
  • Mycobacterial colitis
  • Mycobacterial enteritis of intestine
  • Mycobacterial enteritis of small intestine
  • Non-tuberculous mycobacterial colitis
  • Non-tuberculous mycobacterial enteritis of intestine
  • Non-tuberculous mycobacterial enteritis of small intestine
  • Proteus gastrointestinal tract infection
  • Proteus mirabilis gastrointestinal tract infection
  • Pseudomonas aeruginosa colitis
  • Pseudomonas gastrointestinal tract infection
  • Salmonella gastroenteritis
  • Staphylococcal enterocolitis
  • Staphylococcal gastroenteritis
  • Staphylococcal gastrointestinal tract infection

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.

    • Colitis(acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)
      • staphylococcal
    • Diarrhea, diarrheal(disease) (infantile) (inflammatory)
      • due to
        • bacteria
          • specified NEC
    • Diarrhea, diarrheal(disease) (infantile) (inflammatory)
      • due to
        • Clostridium perfringens (C) (F)
    • Diarrhea, diarrheal(disease) (infantile) (inflammatory)
      • due to
        • specified organism NEC
          • bacterial
    • Diarrhea, diarrheal(disease) (infantile) (inflammatory)
      • due to
        • Staphylococcus
    • Diarrhea, diarrheal(disease) (infantile) (inflammatory)
      • specified
        • bacterium NEC
    • Enteritis(acute) (diarrheal) (hemorrhagic) (noninfective)
      • bacterial
        • specified NEC
    • Enteritis(acute) (diarrheal) (hemorrhagic) (noninfective)
      • infectious NOS
        • due to
          • Aerobacter aerogenes
    • Enteritis(acute) (diarrheal) (hemorrhagic) (noninfective)
      • infectious NOS
        • due to
          • bacteria NOS
            • specified NEC
    • Enteritis(acute) (diarrheal) (hemorrhagic) (noninfective)
      • infectious NOS
        • due to
          • Clostridium perfringens
    • Enteritis(acute) (diarrheal) (hemorrhagic) (noninfective)
      • infectious NOS
        • due to
          • Enterobacter aerogenes
    • Enteritis(acute) (diarrheal) (hemorrhagic) (noninfective)
      • infectious NOS
        • due to
          • specified
            • bacteria NEC
    • Enteritis(acute) (diarrheal) (hemorrhagic) (noninfective)
      • infectious NOS
        • due to
          • Staphylococcus
    • Enteritis(acute) (diarrheal) (hemorrhagic) (noninfective)
      • staphylococcal
    • Infection, infected, infective(opportunistic)
      • Helicobacter pylori
    • Pseudotuberculosis
      • enterocolitis

Clinical ClassificationClinical

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

CCSR INF003
Bacterial infections
Default principal diagnosis: inpatient No · outpatient No
CCSR DIG001
Intestinal infection
Default principal diagnosis: inpatient Yes · outpatient Yes

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 A04.8 to ICD-9-CMHistory

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

ICD-9-CM
008.2 Aerobacter enteritis
Approximate The match is approximate rather than exact.
ICD-9-CM
008.41 Staphylococc enteritis
Approximate The match is approximate rather than exact.
ICD-9-CM
008.49 Bacterial enteritis 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 A04.8Overview

Is A04.8 (Other bacterial intestinal infections) a billable code?

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

What MS-DRG does A04.8 group to?

When other specified bacterial intestinal infections is the principal diagnosis on an inpatient stay, it groups to MS-DRG 371, 372, 373, with relative weights from 0.7274 to 1.7731 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A04.8?

Under the General Equivalence Mappings, other specified bacterial intestinal infections converts to ICD-9-CM 008.2 (aerobacter enteritis), 008.41 (staphylococc enteritis), and 008.49 (bacterial enteritis 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.