What is the ICD-10 code for melanoma?

The ICD-10-CM code for melanoma is C43.9 when documented without further specification. More specific documentation changes the code — see the scenario table.

Yes — C43.9 is a billable ICD-10-CM code, but payers expect the most specific code the documentation supports.

ICD-10 Code for melanoma

The ICD-10-CM code for melanoma is C43.9 when documented without further specification. HCC RxHCC Malignant melanoma of the skin codes in category C43. C43.9 is an unspecified site. Code selection is driven by the anatomic skin site - lip (C43.0), eyelid including canthus (C43.1-), ear and external auricular canal (C43.2-) - and, for paired sites, laterality (right, left).

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Symptom code vs. confirmed diagnosis

C43.9 is a confirmed-diagnosis code for a documented malignant melanoma, assigned from pathology, not a symptom or screening code. Documentation of the specific skin site and, for paired sites, the laterality moves the coder off the unspecified C43.9.

Which Code Should You Use?

C43.9 ✓ Billable — Malignant melanoma of skin, unspecified

Malignant melanoma of skin, unspecified site.

C43.0 ✓ Billable — Malignant melanoma of lip

Malignant melanoma of the lip.

C43.10 ✓ Billable — Malignant melanoma of unspecified eyelid, including canthus

Malignant melanoma of unspecified eyelid, including canthus.

C43.111 ✓ Billable — Malignant melanoma of right upper eyelid, including canthus

Malignant melanoma of right upper eyelid, including canthus.

C43.112 ✓ Billable — Malignant melanoma of right lower eyelid, including canthus

Malignant melanoma of right lower eyelid, including canthus.

What to Document

The anatomic skin site - lip (C43.0), eyelid including canthus (C43.1-), ear and external auricular canal (C43.2-), or another site.
Laterality for paired sites - right versus left eyelid or ear (e.g., C43.111 right upper eyelid).
The histology/morphology as documented by pathology (that the lesion is a malignant melanoma).

Common Documentation Pitfalls

Do not leave melanoma at the unspecified-site C43.9 when the skin site is documented - a specific C43 code applies.
For paired sites (eyelid, ear), laterality and sub-site are part of the code - confirm them (e.g., right upper eyelid C43.111 vs right lower eyelid C43.112).

Also Known As

Official ICD-10-CM Alphabetic Index terms that point to C43.9:

Melanoma (malignant)
Melanoma (malignant) › skin
Melanoma (malignant) › skin › skin NEC

Coding Notes

C43.9 is malignant melanoma of skin, unspecified site. The documented anatomic site - lip (C43.0), eyelid (C43.1-), ear (C43.2-), and others - and, for paired sites, laterality drive a specific C43 code. The unspecified default should be rare when the pathology and site are recorded.

Prevalence & Statistics

In 2023, an estimated 1,573,288 people in the United States were living with melanoma of the skin. (NCI SEER Cancer Stat Facts: Melanoma of the Skin, 2023)