C43.9 Malignant melanoma of skin, unspecified

Billable ICD-10-CM code, FY2026.

Applicable to

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

Applies from C43 Malignant melanoma of skin

Excludes1 (never code together)

• melanoma in situ (D03.-)

Excludes2 (not included here)

• 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

Risk adjustment (HCC)

• CMS-HCC V28: HCC 23 — Prostate, Breast, and Other Cancers and Tumors
• CMS-HCC V22: HCC 12 — Breast, Prostate, and Other Cancers and Tumors
• RxHCC V08: HCC 22 — Prostate, Breast, Bladder, and Other Cancers and Tumors
• ESRD V24: HCC 12

MS-DRG index

Defines the logic of DRG(s) 595-596 in MDC 09.

Approximate ICD-9-CM (GEMs)

• 172.9 Melanoma of skin, site unspecified (approximate)

Code annotations containing back-references to C43.9

Back-references to C43

• Type 1 Excludes: C44 Other and unspecified malignant neoplasm of skin ("malignant melanoma of skin (C43.-)")

Diagnosis Index entries for C43.9

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

Nearby codes

• C43.7 Malignant melanoma of lower limb, including hip
• C43.70 Malignant melanoma of unspecified lower limb, including hip
• C43.71 Malignant melanoma of right lower limb, including hip
• C43.72 Malignant melanoma of left lower limb, including hip
• C43.8 Malignant melanoma of overlapping sites of skin
• C43.9 Malignant melanoma of skin, unspecified (this code)