C4A.3Header code — not billable

Merkel cell carcinoma of other and unspecified parts of face

Chapter
2. Neoplasms
Category
C4A
Effective date
October 1, 2026

Related codes in category C4A

Frequently asked questions

What is ICD-10 code C4A.3?

C4A.3 is an ICD-10-CM diagnosis code for Merkel cell carcinoma of other and unspecified parts of face.

Is C4A.3 a billable code?

No. C4A.3 is a category/header code, not billable on its own — use one of its more specific child codes instead.

What ICD-10-CM chapter is C4A.3 in?

C4A.3 falls under Chapter 2: Neoplasms.

When did C4A.3 become effective?

C4A.3 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.

What other codes are related to C4A.3?

C4A.3 belongs to category C4A, which includes 12 other codes — see the related codes list on this page.

ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.