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C43

C43Malignant melanoma of skin

Non-billable headerICD-10-CM

C43 is a non-billable header ICD-10-CM code for malignant melanoma of skin. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

  • melanoma in situ (D03.-)

Excludes2 — not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

  • malignant melanoma of skin of genital organs (C51-C52, C60.-, C63.-)
  • Merkel cell carcinoma (C4A.-)
  • sites other than skin-code to malignant neoplasm of the site

Other codes that can never be billed with C43

These codes carry an Excludes1 note pointing at C43. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading C43 alone.

  • C69Malignant neoplasm of eye and adnexa
  • C00Malignant neoplasm of lip
  • C30.0Malignant neoplasm of nasal cavity
  • C30.1Malignant neoplasm of middle ear
  • C44Other and unspecified malignant neoplasm of skin

Risk adjustment

C43 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead C43

10 child codes. Green means billable.

Questions about C43

Is C43 a billable ICD-10-CM code?
No. C43 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does C43 sit in the tabular list?
Neoplasms (C00-D49), in the block Melanoma and other malignant neoplasms of skin (C43-C44).
What cannot be coded together with C43?
C43 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.