C4A.4
BillableMerkel cell carcinoma of scalp and neck
Merkel cell carcinoma of scalp and neck
Cross-references
UMLS
Related Codes(9)
C4A.0Merkel cell carcinoma of lip
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.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.4 differs from sibling codes
All children of C4A share the same parent. The wording below is what mechanically separates each sibling from C4A.4.
C4A.0BillableMerkel cell carcinoma of lip
Specifier: "lip" vs. "scalp and neck" in C4A.4.
C4A.1Merkel cell carcinoma of eyelid, including canthus
Specifier: "eyelid, including canthus" vs. "scalp and neck" in C4A.4.
C4A.2Merkel cell carcinoma of ear and external auricular canal
Specifier: "ear and external auricular canal" vs. "scalp and neck" in C4A.4.
C4A.3Merkel cell carcinoma of other and unspecified parts of face
Specifier: "other and unspecified parts of face" vs. "scalp and neck" in C4A.4.
C4A.5Merkel cell carcinoma of trunk
Specifier: "trunk" vs. "scalp and neck" in C4A.4.
C4A.6Merkel cell carcinoma of upper limb, including shoulder
Specifier: "upper limb, including shoulder" vs. "scalp and neck" in C4A.4.
C4A.7Merkel cell carcinoma of lower limb, including hip
Specifier: "lower limb, including hip" vs. "scalp and neck" in C4A.4.
C4A.8BillableMerkel cell carcinoma of overlapping sites
Specifier: "overlapping sites" vs. "scalp and neck" in C4A.4.
C4A.9BillableMerkel cell carcinoma, unspecified
Specifier: "unspecified" vs. "of scalp and neck" in C4A.4.
Also Known As / Clinical Terms(10)
SNOMED CT
Clinical Terms
- Merkel cell carcinoma of scalp
- Malignant neoplasm of skin of scalp
- Malignant neoplasm of scalp
- Merkel cell carcinoma of neck
Common questions
What is the ICD-10-CM code for Merkel cell carcinoma of scalp and neck?
Merkel cell carcinoma of scalp and neck is coded as C4A.4 in ICD-10-CM.
What is ICD-10 code C4A.4?
C4A.4 is the ICD-10-CM identifier for Merkel cell carcinoma of scalp and neck. It is included in the official 2025 release of ICD-10-CM published by CMS and NCHS.
Is C4A.4 a billable code?
Yes, C4A.4 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.4?
C4A.4 sits under C4A (Merkel cell carcinoma) in the ICD-10-CM hierarchy.
What chapter does C4A.4 belong to?
C4A.4 is in Chapter 2: Neoplasms.
What are the synonyms for Merkel cell carcinoma of scalp and neck?
In clinical text, merkel cell carcinoma of scalp and neck is also written as: Malignant neoplasm of scalp, Malignant neoplasm of skin of scalp, Merkel cell carcinoma of neck, Merkel cell carcinoma of scalp. Sourced from SNOMED CT, UMLS Metathesaurus, and clinical-terms enrichment.
Why does C4A.4 map to multiple SNOMED CT concepts?
ICD-10-CM is a billing classification with broader categories than SNOMED CT’s clinical terminology. C4A.4 captures the billing-level concept; SNOMED CT splits it into 3 clinical concepts: 133851000119107, 133861000119109, 188103003.
Automate ICD-10 Coding With AI
Send clinical text to the AutoICD API and get back structured ICD-10 codes with confidence scores. Integrates into any EHR or billing system in minutes.
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.