ICD-10 Code C17 – Malignant neoplasm of small intestine (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C17 – Malignant neoplasm of small intestine
What it is
C17 identifies a malignant tumor arising in the small intestine. Use it when the documentation states a primary cancer of the duodenum, jejunum, or ileum and does not specify a more exact site.
Clinical signs
Clinical features vary; refer to documentation. Patients may present with abdominal pain, obstruction, bleeding, weight loss, or anemia, but the diagnosis should be supported by imaging, endoscopy, pathology, or operative findings.
When to use this code
Use C17 when the provider documents a primary malignant neoplasm of the small intestine and no subsite code is recorded. It also fits cases where the tumor is confirmed but the exact anatomic location within the small intestine is not stated. Check the record for histology and site specificity before assigning the code.
Do not use for
Do not use C17 for benign small intestine tumors, metastatic disease to the small intestine, or cancers documented as arising in another digestive organ. If the site is uncertain, check documentation.
Coding tip
Always code the most specific small-intestine site documented; if the provider names a subsite, use that instead of the unspecified code.