Skip to main content

C26.9 vs D37.9

C26.9 (Malignant neoplasm of ill-defined sites within the digestive system) compared with D37.9 (Neoplasm of uncertain behavior of digestive organ, unspecified), from the official CMS tabular data. C26.9 and D37.9 name the same anatomical site (alimentary canal or tract) with a different neoplasm behavior.

Relationship

Informational

Neoplasm table relationship

C26.9
Malignant neoplasm of ill-defined sites within the digestive system
↔
D37.9
Neoplasm of uncertain behavior of digestive organ, unspecified

Same anatomical site, different neoplasm behavior.

Same site — uncertain behavior (alimentary canal or tract)

The behavior documented for the site — malignant primary, secondary, carcinoma in situ, benign, uncertain or unspecified — decides which column of the neoplasm table, and therefore which code, applies.

Source: CMS Table of Neoplasms

Can these codes be reported together?

Same site, different neoplasm behavior. C26.9 and D37.9 name the same anatomical site (alimentary canal or tract) with a different neoplasm behavior.

From the CMS Table of Neoplasms: the behavior documented for that site — malignant primary, secondary, carcinoma in situ, benign, uncertain or unspecified — decides which column, and therefore which code, applies.

Side by side

C26.9Malignant neoplasm of ill-defined sites within the digestive systemD37.9Neoplasm of uncertain behavior of digestive organ, unspecified
Billing statusBillableBillable
ClassificationC00-D49 — Neoplasms (C00-D49)C00-D49 — Neoplasms (C00-D49)
DefinitionMalignant neoplasm of ill-defined sites within the digestive system is a billable ICD-10-CM diagnosis code (C26.9).Neoplasm of uncertain behavior of digestive organ, unspecified is a billable ICD-10-CM diagnosis code (D37.9).
Includes
Malignant neoplasm of alimentary canal or tract NOS
Malignant neoplasm of gastrointestinal tract NOS
—
Edit this comparisonCheck a whole claim

Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources