Billable / Specific Code
ICD-10-CM C4A.51 is the diagnosis code for Merkel cell carcinoma of anal skin. 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.
Understanding where C4A.51 sits in the ICD-10-CM classification helps ensure proper coding:
Yes, C4A.51 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
C4A.51 is the ICD-10-CM diagnosis code for "Merkel cell carcinoma of anal skin". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of C4A.51 is C4A.5 ("Merkel cell carcinoma of trunk"). C4A.51 provides a more specific classification within this category.
C4A.51 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.51 when the patients documented diagnosis matches "Merkel cell carcinoma of anal skin" 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 anal skin is C4A.51.
Yes, C4A.51 can be used as a primary diagnosis code since it is billable and specific.
C4A.51 is in Chapter 2 of the ICD-10-CM Tabular List.
Yes, C4A.51 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.