C43 vs D03

C43 (Malignant melanoma of skin) compared with D03 (Melanoma in situ), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.

Can these codes be reported together?

No — do not report together. C43 carries an Excludes1 note covering D03: “melanoma in situ (D03.-)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Side by side

	C43Malignant melanoma of skin	D03Melanoma in situ
Billing status	Non-billable header Report instead: C43.0, C43.10, C43.111, C43.112, C43.121	Non-billable header Report instead: D03.0, D03.10, D03.111, D03.112, D03.121
Classification	C00-D49 — Neoplasms (C00-D49)	C00-D49 — Neoplasms (C00-D49)
Definition	Malignant melanoma of skin is a non-billable ICD-10-CM category code (C43).	Melanoma in situ is a non-billable ICD-10-CM category code (D03).
Includes	—	Bowen's disease erythroplasia grade III intraepithelial neoplasia Queyrat's erythroplasia

Edit this comparison Check 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