ICD-10 Code C16.1 – Malignant neoplasm of fundus of stomach (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C16.1 – Malignant neoplasm of fundus of stomach
What it is
C16.1 identifies a malignant tumor located in the fundus of the stomach. Use it when documentation specifies cancer arising in that gastric region, not just a general stomach malignancy.
Clinical signs
Clinical features vary; refer to documentation. Patients may have nonspecific upper gastrointestinal symptoms, but the code is based on the documented anatomic site, not symptom pattern.
When to use this code
Use C16.1 when the provider documents primary malignant neoplasm of the fundus of the stomach. It also fits when pathology, imaging, or operative reports clearly localize the cancer to the fundus. If the record only says “gastric cancer” or another stomach site, check documentation before assigning this code.
Do not use for
Do not use C16.1 for benign gastric lesions, metastatic disease to the stomach, or malignancy documented in a different stomach region. If the fundus is not specified, choose the more accurate documented code or query.
Coding tip
Code the exact stomach subsite only when the record supports it; otherwise, query for clarification.