C4A.20
BillableMerkel cell carcinoma of unsp ear and external auric canal
Merkel cell carcinoma of unspecified ear and external auricular canal
Cross-references
SNOMED CT
UMLS
Related Codes(2)
How C4A.20 differs from sibling codes
All children of C4A.2 share the same parent. The wording below is what mechanically separates each sibling from C4A.20.
Also Known As / Clinical Terms(7)
SNOMED CT
UMLS
Clinical Terms
- Primary Merkel cell carcinoma of skin of ear
- Primary malignant neoplasm of skin of ear
Common questions
What is the ICD-10-CM code for Merkel cell carcinoma of unsp ear and external auric canal?
Merkel cell carcinoma of unsp ear and external auric canal is coded as C4A.20 in ICD-10-CM.
What is ICD-10 code C4A.20?
C4A.20 is the ICD-10-CM identifier for Merkel cell carcinoma of unsp ear and external auric canal. It is included in the official 2025 release of ICD-10-CM published by CMS and NCHS.
Is C4A.20 a billable code?
Yes, C4A.20 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.20?
C4A.20 sits under C4A.2 (Merkel cell carcinoma of ear and external auricular canal) in the ICD-10-CM hierarchy.
What chapter does C4A.20 belong to?
C4A.20 is in Chapter 2: Neoplasms.
What are the synonyms for Merkel cell carcinoma of unsp ear and external auric canal?
In clinical text, merkel cell carcinoma of unsp ear and external auric canal is also written as: Primary Merkel cell carcinoma of skin of ear, Primary malignant neoplasm of skin of ear, Merkel Cell Carcinoma of Unspecified Ear and External Auricular Canal, Merkel cell carcinoma of unspecified ear and external auricular canal. Sourced from SNOMED CT, UMLS Metathesaurus, and clinical-terms enrichment.
Why does C4A.20 map to multiple SNOMED CT concepts?
ICD-10-CM is a billing classification with broader categories than SNOMED CT’s clinical terminology. C4A.20 captures the billing-level concept; SNOMED CT splits it into 2 clinical concepts: 1286951008, 94017001.
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.