C4A.2
Non-billableMerkel cell carcinoma of ear and external auricular canal
Merkel cell carcinoma of ear and external auricular canal
This is a header/category code. For billing purposes, use a more specific child code from the list below.
Cross-references
UMLS
Child Codes (3)
Related Codes(9)
C4A.0Merkel cell carcinoma of lip
C4A.1Merkel cell carcinoma of eyelid, including canthus
C4A.3Merkel cell carcinoma of other and unspecified parts of face
C4A.4Merkel cell carcinoma of scalp and neck
C4A.5Merkel cell carcinoma of trunk
C4A.6Merkel cell carcinoma of upper limb, including shoulder
C4A.7Merkel cell carcinoma of lower limb, including hip
C4A.8Merkel cell carcinoma of overlapping sites
C4A.9Merkel cell carcinoma, unspecified
How C4A.2 differs from sibling codes
All children of C4A share the same parent. The wording below is what mechanically separates each sibling from C4A.2.
C4A.0BillableMerkel cell carcinoma of lip
Specifier: "lip" vs. "ear and external auricular canal" in C4A.2.
C4A.1Merkel cell carcinoma of eyelid, including canthus
Specifier: "eyelid, including canthus" vs. "ear and external auricular canal" in C4A.2.
C4A.3Merkel cell carcinoma of other and unspecified parts of face
Specifier: "other and unspecified parts of face" vs. "ear and external auricular canal" in C4A.2.
C4A.4BillableMerkel cell carcinoma of scalp and neck
Specifier: "scalp and neck" vs. "ear and external auricular canal" in C4A.2.
C4A.5Merkel cell carcinoma of trunk
Specifier: "trunk" vs. "ear and external auricular canal" in C4A.2.
C4A.6Merkel cell carcinoma of upper limb, including shoulder
Specifier: "upper limb, including shoulder" vs. "ear and external auricular canal" in C4A.2.
C4A.7Merkel cell carcinoma of lower limb, including hip
Specifier: "lower limb, including hip" vs. "ear and external auricular canal" in C4A.2.
C4A.8BillableMerkel cell carcinoma of overlapping sites
Specifier: "overlapping sites" vs. "ear and external auricular canal" in C4A.2.
C4A.9BillableMerkel cell carcinoma, unspecified
Specifier: "unspecified" vs. "of ear and external auricular canal" in C4A.2.
Also Known As / Clinical Terms(1)
Common questions
What is the ICD-10-CM code for Merkel cell carcinoma of ear and external auricular canal?
Merkel cell carcinoma of ear and external auricular canal is coded as C4A.2 in ICD-10-CM.
What is ICD-10 code C4A.2?
C4A.2 is the ICD-10-CM identifier for Merkel cell carcinoma of ear and external auricular canal. It is included in the official 2025 release of ICD-10-CM published by CMS and NCHS.
Why is C4A.2 non-billable?
C4A.2 is a category code; ICD-10-CM requires the most specific child code for claim submission. The billable child codes under C4A.2 are: C4A.20, C4A.21, C4A.22.
What is the parent code of C4A.2?
C4A.2 sits under C4A (Merkel cell carcinoma) in the ICD-10-CM hierarchy.
What chapter does C4A.2 belong to?
C4A.2 is in Chapter 2: Neoplasms.
What is the UMLS mapping for C4A.2?
C4A.2 maps to UMLS C2842053.
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Includes SNOMED Clinical Terms® (SNOMED CT®) used by permission of SNOMED International. Includes content from the UMLS Metathesaurus, courtesy of the U.S. National Library of Medicine.