ICD-10 Code A08.11 – Acute gastroenteropathy due to Norwalk agent (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A08.11 – Acute gastroenteropathy due to Norwalk agent
What it is
A08.11 identifies acute gastroenteropathy caused by Norwalk agent, a norovirus infection that affects the stomach and intestines. Use it for acute infectious gastroenteritis when the provider documents Norwalk agent or norovirus.
Clinical signs
Typical findings include sudden nausea, vomiting, diarrhea, abdominal cramps, and short-lived illness. Clinical features vary; refer to documentation, especially when the record links the episode to Norwalk agent or norovirus.
When to use this code
Use this code when the clinician documents acute gastroenteropathy, viral gastroenteritis, or norovirus infection due to Norwalk agent. It fits outpatient, emergency, or inpatient records where the cause is clearly identified and the episode is acute.
If the note only says “gastroenteritis” without an organism, check documentation before assigning A08.11. Code the confirmed cause rather than a nonspecific intestinal infection whenever the record supports it.
Do not use for
Do not use A08.11 for food poisoning, noninfectious diarrhea, or gastroenteritis from another organism. Check documentation if the provider names rotavirus, bacterial infection, or an unspecified cause.
Coding tip
Assign A08.11 only when the chart explicitly ties the acute gastroenteropathy to Norwalk agent or norovirus.