C23 (Malignant neoplasm of gallbladder) compared with D37.6 (Neoplasm of uncertain behavior of liver, gallbladder and bile ducts), from the official CMS tabular data. C23 and D37.6 name the same anatomical site (gallbladder) with a different neoplasm behavior. MedCoder-derived
Same anatomical site, different neoplasm behavior.
Same site — uncertain behavior (gallbladder)
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
Same site, different neoplasm behavior. C23 and D37.6 name the same anatomical site (gallbladder) with a different neoplasm behavior.
From the CMS/CDC 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.
| C23Malignant neoplasm of gallbladder | D37.6Neoplasm of uncertain behavior of liver, gallbladder and bile ducts | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms | C00-D49 — Neoplasms |
| Definition | Malignant neoplasm of gallbladder is a billable ICD-10-CM diagnosis code (C23). | Neoplasm of uncertain behavior of liver, gallbladder and bile ducts is a billable ICD-10-CM diagnosis code (D37.6). |
| Includes | — | Neoplasm of uncertain behavior of ampulla of Vater |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources