The following codes as of January 2019 are provided as a reference and may be relevant when billing for KEYTRUDA and its administration. Consult the relevant manual and/or other guidelines for a description of each code to determine the appropriateness of its use and for information on additional codes. Diagnosis codes should be selected only by a health care professional. You are solely responsible for determining the appropriate codes and for any action you take in billing.

When submitting a claim for KEYTRUDA, always verify coding requirements with the relevant payer. Coding requirements may vary by insurer or plan; please refer to the payer-specific policies to understand what may be covered.

Check with the relevant payer regarding guidance on which diagnoses they will recognize and the applicability of secondary codes. Health care professionals are solely responsible for selecting codes that appropriately reflect the patient’s diagnosis, the services rendered, and the applicable payers’ guidelines.

Providers should document the diagnosis with a sufficiently high degree of specificity based on the information available to enable the identification of the most appropriate code. Although CMS has said that an unspecified code may be appropriate in some cases, CMS has advised that you should always code with as much specificity as possible consistent with the clinical documentation.

Merck and its agents make no warranties concerning the accuracy or appropriateness of this information for your particular use given the frequent changes in public and private payer billing. Merck cautions that payer-coding requirements vary and can frequently change, so it is important to regularly check with each payer or, where applicable, the Medicare Administrative Contractor as to payer-specific requirements. The use of this information does not guarantee payment or that any payment received will cover your costs.


KEYTRUDA is indicated for the treatment of patients with unresectable or metastatic melanoma.

FDA-Approved Dosing

The FDA-approved dose of KEYTRUDA is 200 mg administered as an intravenous infusion over 30 minutes every 3 weeks until disease progression or unacceptable toxicity.

Possible relevant diagnosis codes for advanced melanoma

Learn more about each diagnosis code and descriptor by selecting from the series options below.


C43: Malignant Melanoma of Skin4,5

  • The C43 series excludes: melanoma in situ, malignant melanoma of skin of genital organs, Merkel cell carcinoma, sites other than skin - code to malignant neoplasm of the site; C43.0 excludes malignant neoplasm of vermilion border of lip
C43.0 Malignant melanoma of lip
C43.11 Malignant melanoma of right eyelid, including canthus
C43.12 Malignant melanoma of left eyelid, including canthus
C43.20 Malignant melanoma of unspecified ear and external auricular canal
C43.21 Malignant melanoma of right ear and external auricular canal
C43.22 Malignant melanoma of left ear and external auricular canal
C43.30 Malignant melanoma of unspecified part of face
C43.31 Malignant melanoma of nose
C43.39 Malignant melanoma of other parts of face
C43.4 Malignant melanoma of scalp and neck
C43.51 Malignant melanoma of anal skin
C43.52 Malignant melanoma of skin of breast
C43.59 Malignant melanoma of other part of trunk
C43.60 Malignant melanoma of unspecified upper limb, including shoulder
C43.61 Malignant melanoma of right upper limb, including shoulder
C43.62 Malignant melanoma of left upper limb, including shoulder
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

C21: Malignant Neoplasm of Anus and Anal Canal4

The C21 series:

  • Excludes: malignant carcinoid tumors of the colon, malignant melanoma of anal margin, malignant melanoma of anal skin, malignant melanoma of perianal skin, other and unspecified malignant neoplasm of anal margin, other and unspecified malignant neoplasm of anal skin, other and unspecified malignant neoplasm of perianal skin
C21.0 Malignant neoplasm of anus, unspecified
C21.1 Malignant neoplasm of anal canal

C51: Malignant Neoplasm of Vulva4

The C51 series:

  • Excludes: carcinoma in situ of vulva
C51.0 Malignant neoplasm of labium majus
C51.1 Malignant neoplasm of labium minus
C51.2 Malignant neoplasm of clitoris
C51.8 Malignant neoplasm of overlapping sites of vulva
C51.9 Malignant neoplasm of vulva, unspecified

C60: Malignant Neoplasm of Penis4

C60.0 Malignant neoplasm of prepuce
C60.1 Malignant neoplasm of glans penis
C60.2 Malignant neoplasm of body of penis
C60.8 Malignant neoplasm of overlapping sites of penis
C60.9 Malignant neoplasm of penis, unspecified

C63: Malignant Neoplasm of Other and Unspecified Male Genital Organs4

C63.2 Malignant neoplasm of scrotum
C63.7 Malignant neoplasm of other specified male genital organs
C63.8 Malignant neoplasm of overlapping sites of male genital organs