C79.89 vs D04.6

C79.89 (Secondary malignant neoplasm of other specified sites) compared with D04.6 (Carcinoma in situ of skin of upper limb, including shoulder), from the official CMS tabular data. C79.89 and D04.6 name the same anatomical site (antecubital fossa or space) with a different neoplasm behavior.

Relationship

Informational

Neoplasm table relationship

C79.89

Secondary malignant neoplasm of other specified sites

↔

D04.6

Carcinoma in situ of skin of upper limb, including shoulder

Same anatomical site, different neoplasm behavior.

Same site — carcinoma in situ (antecubital fossa or space)

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. C79.89 and D04.6 name the same anatomical site (antecubital fossa or space) 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

	C79.89Secondary malignant neoplasm of other specified sites	D04.6Carcinoma in situ of skin of upper limb, including shoulder
Billing status	Billable	Non-billable header Report instead: D04.60, D04.61, D04.62
Classification	C00-D49 — Neoplasms (C00-D49)	C00-D49 — Neoplasms (C00-D49)
Definition	Secondary malignant neoplasm of other specified sites is a billable ICD-10-CM diagnosis code (C79.89).	Carcinoma in situ of skin of upper limb, including shoulder is a non-billable ICD-10-CM category code (D04.6).
Includes	—	Bowen's disease erythroplasia grade III intraepithelial neoplasia Queyrat's erythroplasia

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