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  6. 2024 ICD-10-CM Code C4A.5
Version 2024
Non-Billable Code

2024 ICD-10-CM Diagnosis Code C4A.5

Merkel cell carcinoma of trunk

ICD-10-CM Code:
C4A.5
ICD-10 Code for:
Merkel cell carcinoma of trunk
Is Billable?
Not Valid for Submission
Code Navigator:

Code Classification

  • Neoplasms
    (C00–D49)
    • Melanoma and other malignant neoplasms of skin
      (C43-C44)
      • Merkel cell carcinoma
        (C4A)

C4A.5 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of merkel cell carcinoma of trunk. The code is not specific and is NOT valid for the year 2024 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Specific Coding Applicable to Merkel cell carcinoma of trunk

Non-specific codes like C4A.5 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for merkel cell carcinoma of trunk:

  • Use C4A.51 for Merkel cell carcinoma of anal skin - BILLABLE CODE

  • Use C4A.52 for Merkel cell carcinoma of skin of breast - BILLABLE CODE

  • Use C4A.59 for Merkel cell carcinoma of other part of trunk - BILLABLE CODE

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Type 2 Excludes

Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
  • malignant neoplasm of anus NOS C21.0
  • malignant neoplasm of scrotum C63.2

Patient Education


Skin Cancer

Skin cancer is the most common form of cancer in the United States. The two most common types are basal cell cancer and squamous cell cancer. They usually form on the head, face, neck, hands, and arms. Another type of skin cancer, melanoma, is more dangerous but less common.

Anyone can get skin cancer, but it is more common in people who :

  • Spend a lot of time in the sun or have been sunburned
  • Have light-colored skin, hair and eyes
  • Have a family member with skin cancer
  • Are over age 50

You should have your doctor check any suspicious skin markings and any changes in the way your skin looks. Treatment is more likely to work well when cancer is found early. If not treated, some types of skin cancer cells can spread to other tissues and organs. Treatments include surgery, radiation therapy, chemotherapy, photodynamic therapy (PDT), and biologic therapy. PDT uses a drug and a type of laser light to kill cancer cells. Biologic therapy boosts your body's own ability to fight cancer.

NIH: National Cancer Institute


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.