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C51.9

C51.9Malignant neoplasm of vulva, unspecified

Billable / specific codeICD-10-CM

C51.9 is a billable, specific ICD-10-CM code for malignant neoplasm of vulva, unspecified. It is valid for submission on a claim.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Malignant neoplasm of external female genitalia NOS
  • Malignant neoplasm of pudendum

Risk adjustment

C51.9 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:

  • HCC 22 Bladder, Colorectal, and Other Cancers0.363 RAF

Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.

Medicare coverage

C51.9 is named in 46 Medicare coverage policies 46 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A52450Billing and Coding: Paclitaxel (e.g., Taxol®/Abraxane ™)
  • A52479Oral Anticancer Drugs - Policy Article
  • A52480Oral Antiemetic Drugs (Replacement for Intravenous Antiemetics) - Policy Article
  • A55717Billing and Coding: Lab: Flow Cytometry

How C51.9 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to C51.9.

  • Melanomaskinfemale genital organ NEC(external)
  • Melanomaskinlabium
  • Melanomaskinpudendum
  • Melanomaskinvulva

Related codes at this level

Codes that share C51. If C51.9 is not quite right, the correct code is usually one of these.

Questions about C51.9

Is C51.9 a billable ICD-10-CM code?
Yes. C51.9 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does C51.9 sit in the tabular list?
Neoplasms (C00-D49), in the block Malignant neoplasms of female genital organs (C51-C58).
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.