ICD-10 Code D13.99 – Benign neoplasm of ill-defined sites within the digestive system (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D13.99 – Benign neoplasm of ill-defined sites within the digestive system
What it is
This code identifies a noncancerous growth in the digestive system when the exact site is not clearly documented. Use it for benign neoplasms in ill-defined digestive locations, not for malignant or unspecified masses.
Clinical signs
Clinical features vary; refer to documentation. Benign digestive neoplasms may be found on imaging, endoscopy, or pathology after evaluation of a mass, polyp, or incidental lesion.
When to use this code
Use D13.99 when the provider documents a benign neoplasm in the digestive system but does not specify a more precise anatomic site. It fits cases where the record supports benign behavior and the location is described as ill-defined or otherwise not classifiable to a more specific digestive organ. If the site is later clarified, code the more specific diagnosis instead.
Do not use for
Do not use this code for malignant neoplasms, uncertain behavior, or lesions documented as cysts, polyps, or inflammatory masses unless the provider calls them benign neoplasms. Check documentation.
Coding tip
Query for the exact digestive site whenever possible; D13.99 is appropriate only when the record supports benign behavior but remains anatomically nonspecific.