ICD-10 Code C16.8 – Malignant neoplasm of overlapping sites of stomach (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C16.8 – Malignant neoplasm of overlapping sites of stomach
What it is
This code identifies a malignant tumor of the stomach that involves two or more contiguous sites, so no single gastric location fully describes it. Use it when the record documents overlapping involvement rather than one clearly defined stomach subsite.
Clinical signs
Clinical features vary; refer to documentation. Gastric cancer may present with weight loss, abdominal pain, early satiety, nausea, vomiting, or gastrointestinal bleeding, but the site must be recorded as overlapping for this code.
When to use this code
Use C16.8 when the provider documents a primary malignant neoplasm of the stomach spanning adjacent areas, such as the body and antrum, and does not assign a single subsite. It is also appropriate when pathology or imaging supports overlapping gastric involvement. Check documentation if the site description is unclear.
Do not use for
Do not use this code for benign gastric lesions, metastatic disease to the stomach, or a stomach cancer limited to one specific subsite. If the record states only “stomach cancer” without overlap detail, check documentation.
Coding tip
Code the most specific gastric site documented; reserve C16.8 for true overlap of contiguous stomach sites.