Is C4A.1 a billable code?
No. C4A.1 is a header code that groups 5 more specific codes. Use one of the billable codes listed on this page instead.
ICD-10-CM FY2027 diagnosis code
C4A.1: Merkel cell carcinoma of eyelid, including canthus
Header code: not billableValid for dates of service October 1, 2026 to September 30, 2027
C4A.1 groups related diagnoses under merkel cell carcinoma of eyelid, including canthus. It cannot be used on a claim by itself. Choose the billable code below that matches the patient's record.
Billable codes under C4A.1
- C4A.10Merkel cell carcinoma of unspecified eyelid, including canthus
- C4A.111Merkel cell carcinoma of right upper eyelid, including canthus
- C4A.112Merkel cell carcinoma of right lower eyelid, including canthus
- C4A.121Merkel cell carcinoma of left upper eyelid, including canthus
- C4A.122Merkel cell carcinoma of left lower eyelid, including canthus
Other codes in C4A Merkel cell carcinoma
- C4A.0Merkel cell carcinoma of lip
- C4A.2Merkel cell carcinoma of ear and external auricular canalheader
- C4A.3Merkel cell carcinoma of other and unspecified parts of faceheader
- C4A.4Merkel cell carcinoma of scalp and neck
- C4A.5Merkel cell carcinoma of trunkheader
- C4A.6Merkel cell carcinoma of upper limb, including shoulderheader
- C4A.7Merkel cell carcinoma of lower limb, including hipheader
- C4A.8Merkel cell carcinoma of overlapping sites
- C4A.9Merkel cell carcinoma, unspecified
C4A.1 questions
What does C4A.1 mean?
C4A.1 is the ICD-10-CM code for Merkel cell carcinoma of eyelid, including canthus. It is in chapter 2, Neoplasms (C00-D49).
Code titles come from the official ICD-10-CM files published by the CDC National Center for Health Statistics. Always check payer rules and the clinical record before billing.