ICD-10 Code K29 – Gastritis and duodenitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K29 – Gastritis and duodenitis
What it is
K29 identifies inflammation of the stomach lining, the duodenum, or both. Use it when the record documents gastritis, duodenitis, or a combined inflammatory condition without a more specific subtype.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings include upper abdominal pain, nausea, vomiting, dyspepsia, or endoscopic evidence of mucosal inflammation.
When to use this code
Use K29 when the provider diagnoses gastritis and/or duodenitis and does not specify a more detailed code. It also fits cases where the note confirms inflammatory disease of the stomach or duodenum but leaves the cause, acuity, or subtype unclear. Check documentation for any linked etiology.
Do not use for
Do not use K29 for peptic ulcer disease, gastroenteritis, or reflux-related symptoms alone. If the documentation names a specific cause or subtype, code that condition instead.
Coding tip
Look for the exact provider wording and any stated cause, because K29 is often a fallback when the record is nonspecific.