C44.90 (Unspecified malignant neoplasm of skin, unspecified) compared with D23.9 (Other benign neoplasm of skin, unspecified), from the official CMS tabular data. C44.90 and D23.9 name the same anatomical site (connective tissue) with a different neoplasm behavior.
Same anatomical site, different neoplasm behavior.
Same site — benign neoplasm (connective tissue)
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. C44.90 and D23.9 name the same anatomical site (connective tissue) 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.
| C44.90Unspecified malignant neoplasm of skin, unspecified | D23.9Other benign neoplasm of skin, unspecified | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Unspecified malignant neoplasm of skin, unspecified is a billable ICD-10-CM diagnosis code (C44.90). | Other benign neoplasm of skin, unspecified is a billable ICD-10-CM diagnosis code (D23.9). |
| Includes | malignant neoplasm of sebaceous glands malignant neoplasm of sweat glands Malignant neoplasm of unspecified site of skin | benign neoplasm of hair follicles benign neoplasm of sebaceous glands benign neoplasm of sweat glands |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources