ICD-10-CM C4A.0 is the diagnosis code for Merkel cell carcinoma of lip. This code falls under the section "Melanoma and other malignant neoplasms of skin" within Chapter 2 — Neoplasms (C00-D49). It is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
The following conditions should never be coded at the same time as C4A.0. They are mutually exclusive:
Understanding where C4A.0 sits in the ICD-10-CM classification helps ensure proper coding:
Yes, C4A.0 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
C4A.0 is the ICD-10-CM diagnosis code for "Merkel cell carcinoma of lip". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of C4A.0 is C4A ("Merkel cell carcinoma"). C4A.0 provides a more specific classification within this category.
C4A.0 is located in Section C43-C44 — "Melanoma and other malignant neoplasms of skin" within Chapter 2 of the ICD-10-CM Tabular List.
Use C4A.0 when the patients documented diagnosis matches "Merkel cell carcinoma of lip" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Merkel cell carcinoma of lip is C4A.0.
Yes, C4A.0 can be used as a primary diagnosis code since it is billable and specific.
C4A.0 is in Chapter 2 of the ICD-10-CM Tabular List.
Type 1 Excludes for C4A.0 include: malignant neoplasm of vermilion border of lip (C00.0-C00.2).
Yes, C4A.0 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.