C66 (Malignant neoplasm of ureter) compared with D09.19 (Carcinoma in situ of other urinary organs), from the official CMS tabular data. C66 and D09.19 name the same anatomical site (ureter) with a different neoplasm behavior.
Same anatomical site, different neoplasm behavior.
Same site — carcinoma in situ (ureter)
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. C66 and D09.19 name the same anatomical site (ureter) 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.
| C66Malignant neoplasm of ureter | D09.19Carcinoma in situ of other urinary organs | |
|---|---|---|
| Billing status | Non-billable header | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Malignant neoplasm of ureter is a non-billable ICD-10-CM category code (C66). | Carcinoma in situ of other urinary organs is a billable ICD-10-CM diagnosis code (D09.19). |
| Includes | — | Bowen's disease erythroplasia grade III intraepithelial neoplasia Queyrat's erythroplasia |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources