A09
Billable

Infectious gastroenteritis and colitis, unspecified

Billable / Specific Code

What is Infectious gastroenteritis and colitis, unspecified?

ICD-10-CM A09 is the diagnosis code for Infectious gastroenteritis and colitis, unspecified. This code falls under the section "Intestinal infectious diseases" within Chapter 1 — Certain infectious and parasitic diseases (A00-B99). It is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.

💡 Inclusions
⛔ Excludes1

Coding Guidelines for A09

✅ This Code Includes

  • Infectious colitis NOS
  • Infectious enteritis NOS
  • Infectious gastroenteritis NOS

⛔ Type 1 Excludes (Never code together)

The following conditions should never be coded at the same time as A09. They are mutually exclusive:

  • colitis NOS (K52.9)
  • diarrhea NOS (R19.7)
  • enteritis NOS (K52.9)
  • gastroenteritis NOS (K52.9)
  • noninfective gastroenteritis and colitis, unspecified (K52.9)

ICD-10-CM Code Hierarchy

Understanding where A09 sits in the ICD-10-CM classification helps ensure proper coding:

Current CodeA09 — Infectious gastroenteritis and colitis, unspecified
Related Codes

Frequently Asked Questions

Is A09 a billable ICD-10-CM code?

Yes, A09 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.

What does A09 mean?

A09 is the ICD-10-CM diagnosis code for "Infectious gastroenteritis and colitis, unspecified". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.

What section is A09 in?

A09 is located in Section A00-A09 — "Intestinal infectious diseases" within Chapter 1 of the ICD-10-CM Tabular List.

When should I use A09?

Use A09 when the patients documented diagnosis matches "Infectious gastroenteritis and colitis, unspecified" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.

People Also Ask

What is the ICD-10 code for Infectious gastroenteritis and colitis, unspecified?

The ICD-10-CM code for Infectious gastroenteritis and colitis, unspecified is A09.

Can A09 be used for primary diagnosis?

Yes, A09 can be used as a primary diagnosis code since it is billable and specific.

What chapter is A09 in?

A09 is in Chapter 1 of the ICD-10-CM Tabular List.

What conditions are excluded from A09?

Type 1 Excludes for A09 include: colitis NOS (K52.9); diarrhea NOS (R19.7); enteritis NOS (K52.9) and more.

Is A09 valid for 2026?

Yes, A09 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.

See Also

← PreviousA08.8Other specified intestinal infectionsNext →A15Respiratory tuberculosis
Code Details
A09
Infectious gastroenteritis and colitis, unspecified
Billable / Specific Code
1 — Certain infectious and parasitic diseases (A00-B99)
A00-A09 — Intestinal infectious diseases
2026 ICD-10-CM