ICD-10-CM Tabular Index · Chapter 1 · FY 2026 A00–A09

Intestinal infectious diseases (A00-A09) ICD-10-CM

The A00–A09 section covers intestinal infectious diseases with 94 ICD-10-CM diagnosis codes, of which 79 are billable in fiscal year 2026. The section is organized into the 10 code ranges listed below.

✓ Built from the official CMS FY 2026 datasetEffective Oct 1, 2025 – Sep 30, 2026
10
Code Ranges
94
Diagnosis Codes
79
Billable Codes
A00–A09
Code Range
ICD-10-CM

Code Ranges in This Section 10 ranges · 94 codes

About the A00–A09 Code Range

ICD-10 codes A00-A09 cover a range of intestinal infectious diseases caused by various bacteria, protozoa, and viruses that affect the digestive system. These codes are used for diagnosing conditions such as cholera, typhoid, salmonella infections, shigellosis, amebiasis, and several viral gastroenteritis types.

This code range includes Cholera (A00) caused by different Vibrio cholerae biovars, identified using synonyms like intestinal infection caused by Vibrio cholerae. It also categorizes typhoid and paratyphoid fevers (A01), with specific forms such as typhoid fever with meningitis or pneumonia. The salmonella infections (A02) include salmonella enteritis, localized infections, and sepsis, with terms like Salmonella gastroenteritis helping to clarify the coding. Shigellosis (A03) is detailed by the type of Shigella bacteria causing colitis, often referenced as bacterial dysentery. Other bacterial intestinal infections (A04) cover various Escherichia coli and Clostridium difficile infections, including recurrent forms, commonly called Clostridioides difficile infection or traveler’s diarrhea for certain E. coli types. Amebiasis (A06) codes describe protozoal infections like acute and chronic amebic dysentery and related abscesses, with synonyms such as Entamoeba histolytica infection. Additional protozoal diseases (A07), including giardiasis and cryptosporidiosis, and viral intestinal infections (A08), such as rotaviral enteritis and Norwalk virus, further define this chapter. The unspecified category (A09) is used for infectious gastroenteritis and colitis of undetermined cause.

Questions About This Page

How many codes are in the A00-A09 range?

The A00-A09 range contains 94 ICD-10-CM diagnosis codes in FY 2026. 79 of them are billable, and the rest are category headers that organize the section.

What conditions does A00-A09 cover?

The range covers intestinal infectious diseases. The code ranges listed above break it into groups of related conditions, and each one links to its own page with the full code list.

Related References

Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.