C4A

Non-Billable
ChapterC00–D49
Rankcategory
Description

Merkel cell carcinoma

About ICD-10-CM code C4A

C4A is the ICD-10-CM diagnosis code for Merkel cell carcinoma. It sits in C00-D49 Neoplasms, within Melanoma and other malignant neoplasms of skin (C43-C44). C4A is not billable on its own, coders must choose one of its more specific child codes instead.

Metadata & Insights
  • Non-billable category (requires more specific sub-code).
  • Chapter 2: Neoplasms (C00-D49).

Clinical Hierarchy

BillableHas subcodes
CH2Neoplasms (C00-D49)
C43-C44Melanoma and other malignant neoplasms of skin (C43-C44)
C4AMerkel cell carcinomaNot billable
C4A.0Merkel cell carcinoma of lipBillable
C4A.1Merkel cell carcinoma of eyelid, including canthusSubcodes
C4A.2Merkel cell carcinoma of ear and external auricular canalSubcodes
C4A.3Merkel cell carcinoma of other and unspecified parts of faceSubcodes
C4A.4Merkel cell carcinoma of scalp and neckBillable
C4A.5Merkel cell carcinoma of trunkSubcodes
C4A.6Merkel cell carcinoma of upper limb, including shoulderSubcodes
C4A.7Merkel cell carcinoma of lower limb, including hipSubcodes
C4A.8Merkel cell carcinoma of overlapping sitesBillable
C4A.9Merkel cell carcinoma, unspecifiedBillable

MS-DRG Classification

2026

No direct MS-DRG triggers identified.

Cross Reference

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