C4A.0
BillableMerkel cell carcinoma of lip
Merkel cell carcinoma of lip
Cross-references
SNOMED CT
UMLS
Coding Notes
Excludes 1
Codes that cannot be used together with this code (mutual exclusion)
Related Codes(9)
C4A.1Merkel cell carcinoma of eyelid, including canthus
C4A.2Merkel cell carcinoma of ear and external auricular canal
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.0 differs from sibling codes
All children of C4A share the same parent. The wording below is what mechanically separates each sibling from C4A.0.
C4A.1Merkel cell carcinoma of eyelid, including canthus
Specifier: "eyelid, including canthus" vs. "lip" in C4A.0.
C4A.2Merkel cell carcinoma of ear and external auricular canal
Specifier: "ear and external auricular canal" vs. "lip" in C4A.0.
C4A.3Merkel cell carcinoma of other and unspecified parts of face
Specifier: "other and unspecified parts of face" vs. "lip" in C4A.0.
C4A.4BillableMerkel cell carcinoma of scalp and neck
Specifier: "scalp and neck" vs. "lip" in C4A.0.
C4A.5Merkel cell carcinoma of trunk
Wording: "trunk" vs. "lip" in C4A.0.
C4A.6Merkel cell carcinoma of upper limb, including shoulder
Specifier: "upper limb, including shoulder" vs. "lip" in C4A.0.
C4A.7Merkel cell carcinoma of lower limb, including hip
Specifier: "lower limb, including hip" vs. "lip" in C4A.0.
C4A.8BillableMerkel cell carcinoma of overlapping sites
Specifier: "overlapping sites" vs. "lip" in C4A.0.
C4A.9BillableMerkel cell carcinoma, unspecified
Specifier: "unspecified" vs. "of lip" in C4A.0.
Also Known As / Clinical Terms(8)
SNOMED CT
Clinical Terms
- Primary malignant neoplasm of skin of lip
- Primary carcinoma of lip
- Primary Merkel cell carcinoma of skin of lip
Common questions
What is the ICD-10-CM code for Merkel cell carcinoma of lip?
Merkel cell carcinoma of lip is coded as C4A.0 in ICD-10-CM.
What is ICD-10 code C4A.0?
C4A.0 is the ICD-10-CM identifier for Merkel cell carcinoma of lip. It is included in the official 2025 release of ICD-10-CM published by CMS and NCHS.
Is C4A.0 a billable code?
Yes, C4A.0 is a billable / specific ICD-10-CM code that can be used to indicate a diagnosis on a medical claim.
What is the parent code of C4A.0?
C4A.0 sits under C4A (Merkel cell carcinoma) in the ICD-10-CM hierarchy.
What chapter does C4A.0 belong to?
C4A.0 is in Chapter 2: Neoplasms.
What are the synonyms for Merkel cell carcinoma of lip?
In clinical text, merkel cell carcinoma of lip is also written as: Primary Merkel cell carcinoma of skin of lip, Primary carcinoma of lip, Primary malignant neoplasm of skin of lip. Sourced from SNOMED CT, UMLS Metathesaurus, and clinical-terms enrichment.
Why does C4A.0 map to multiple SNOMED CT concepts?
ICD-10-CM is a billing classification with broader categories than SNOMED CT’s clinical terminology. C4A.0 captures the billing-level concept; SNOMED CT splits it into 3 clinical concepts: 1259434000, 352081000119108, 94032008.
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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.