ICDcodes.org
FY2027

C43.9 — Malignant melanoma of skin, unspecified

BillableUnspecified

Is C43.9 billable?

Yes, but C43.9 is an unspecified code. C43.9 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, C43.9 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting C43.9 — the more specific alternatives are listed below.

C43.9 at a glance

CodeC43.9
DescriptionMalignant melanoma of skin, unspecified
BillableYes
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027

Which MS-DRGs does C43.9 group to?

C43.9 sits in MDC 09 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

  • 595Major Skin Disorders with MCCmedical
  • 596Major Skin Disorders without MCCmedical

How is C43.9 listed in the Alphabetic Index?

These are the routes through the Alphabetic Index that lead to C43.9. They show the wording a clinician may have documented, which often differs from the Tabular description.

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

Inclusion terms

Alternative wording in documentation that is classified to C43.9.

  • Malignant melanoma of unspecified site of skin
  • Melanoma (malignant) NOS

Excludes1 — never code together — inherited from C43

The conditions below can never be reported together with C43.9 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.

Excludes2 — not included here — inherited from C43

The conditions below are not part of C43.9, but a patient may have both at the same time. When documentation supports it, C43.9 and the excluded code may both be reported.

  • 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

How long has C43.9 existed?

C43.9 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.

Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.

Which conditions are coded to C43.9?

What other codes are in the C43 family? (9)