ICD-10-CM Code C4A.12

Merkel cell carcinoma of left eyelid, including canthus

Version 2020 Replaced Code Non-Billable Code

Not Valid for Submission

C4A.12 is a "header" nonspecific and non-billable code code, consider using a code with a higher level of specificity for a diagnosis of merkel cell carcinoma of left eyelid, including canthus. The code is NOT valid for the year 2020 for the submission of HIPAA-covered transactions.

ICD-10:C4A.12
Short Description:Merkel cell carcinoma of left eyelid, including canthus
Long Description:Merkel cell carcinoma of left eyelid, including canthus

Consider the following ICD-10 codes with a higher level of specificity:

  • C4A.121 - Merkel cell carcinoma of left upper eyelid, including canthus
  • C4A.122 - Merkel cell carcinoma of left lower eyelid, including canthus

Replaced Code

This code was replaced in the 2020 ICD-10 code set with the code(s) listed below. The National Center for Health Statistics (NCHS) has published an update to the ICD-10-CM diagnosis codes which became effective October 1, 2019. This code was replaced for the FY 2020 (October 1, 2019 - September 30, 2020).

  • C4A.121 - Merkel cell carcinoma of left upper eyelid, inc canthus
  • C4A.122 - Merkel cell carcinoma of left lower eyelid, inc canthus

Convert C4A.12 to ICD-9

  • 209.31 - Merkel cell ca-face (Approximate Flag)

Code Classification

  • Neoplasms (C00–D48)
    • Melanoma and other malignant neoplasms of skin (C43-C44)
      • Merkel cell carcinoma (C4A)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - Code Deleted, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020

Information for Patients


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


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