C4A.9
BillableMerkel cell carcinoma, unspecified
Merkel cell carcinoma, unspecified
Cross-references
Coding Notes
Inclusion Terms
Alternative clinical terms for this condition
- Merkel cell carcinoma of unspecified site
- Merkel cell carcinoma NOS
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.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
How C4A.9 differs from sibling codes
All children of C4A share the same parent. The wording below is what mechanically separates each sibling from C4A.9.
C4A.0BillableMerkel cell carcinoma of lip
Specifier: "of lip" vs. "unspecified" in C4A.9.
C4A.1Merkel cell carcinoma of eyelid, including canthus
Specifier: "of eyelid, including canthus" vs. "unspecified" in C4A.9.
C4A.2Merkel cell carcinoma of ear and external auricular canal
Specifier: "of ear and external auricular canal" vs. "unspecified" in C4A.9.
C4A.3Merkel cell carcinoma of other and unspecified parts of face
Specifier: "of other and unspecified parts of face" vs. "unspecified" in C4A.9.
C4A.4BillableMerkel cell carcinoma of scalp and neck
Specifier: "of scalp and neck" vs. "unspecified" in C4A.9.
C4A.5Merkel cell carcinoma of trunk
Specifier: "of trunk" vs. "unspecified" in C4A.9.
C4A.6Merkel cell carcinoma of upper limb, including shoulder
Specifier: "of upper limb, including shoulder" vs. "unspecified" in C4A.9.
C4A.7Merkel cell carcinoma of lower limb, including hip
Specifier: "of lower limb, including hip" vs. "unspecified" in C4A.9.
C4A.8BillableMerkel cell carcinoma of overlapping sites
Specifier: "of overlapping sites" vs. "unspecified" in C4A.9.
Also Known As / Clinical Terms(102)
SNOMED CT
- Cancer metastatic to liver94381002
- Hepatic metastasis94381002
- Liver secondaries94381002
- Liver secondary cancer94381002
- Metastasis to liver94381002
- Metastatic malignant neoplasm of liver94381002
- Metastatic malignant neoplasm to liver94381002
- Secondary malignancy of liver94381002
- Secondary malignant neoplasm of liver94381002
- Merkel cell carcinoma253001006
- Merkel cell tumor253001006
- Merkel cell tumour253001006
- Neuroendocrine neoplasm of liver1290081007
- Metastatic Merkel cell carcinoma of liver14914931000119107
- Metastatic Merkel cell carcinoma to liver14914931000119107
- Secondary Merkel cell carcinoma of liver14914931000119107
- Metastatic Merkel cell carcinoma of skin14914851000119109
- Metastatic Merkel cell carcinoma to skin14914851000119109
- Secondary Merkel cell carcinoma of skin14914851000119109
UMLS
- Anaplastic carcinoma of the skinC0007129
- Apudoma of skinC0007129
- Apudoma of skin (disorder)C0007129
- Cancer, Merkel CellC0007129
- Carcinoma, Merkel CellC0007129
- Cell Cancer, MerkelC0007129
- Cutaneous APUDomaC0007129
- MCCC0007129
- Merkel Cell CancerC0007129
- Merkel Cell CarcinomaC0007129
- Merkel Cell TumorC0007129
- Merkel cell cancer of the skinC0007129
- Merkel cell carcinomaC0007129
- Merkel cell carcinoma (disorder)C0007129
- Merkel cell carcinoma (morphologic abnormality)C0007129
- Merkel cell carcinoma NOSC0007129
- Merkel cell skin cancerC0007129
- Merkel cell tumorC0007129
- Merkel cell tumourC0007129
- Merkle TumorsC0007129
- Neuroendocrine carcinoma of the skinC0007129
- Neuroendocrine tumor of the skinC0007129
- Neuroendocrine tumour of the skinC0007129
- Primary cutaneous neuroendocrine carcinomaC0007129
- Primary small cell carcinoma of the skinC0007129
- Primary undifferentiated carcinoma of the skinC0007129
- Tumor, Merkel CellC0007129
- Tumors, MerkleC0007129
- carcinoma cell merkelsC0007129
- carcinoma neuroendocrine skinC0007129
- cell merkel tumorsC0007129
- mccC0007129
- merkel cell cancerC0007129
- merkel cell carcinomaC0007129
- merkel cell tumorC0007129
- merkel cell tumourC0007129
- Merkel cell carcinoma of unspecified siteC2977927
- Merkel cell carcinoma, unspecifiedC2842075
Clinical Terms
- Metastatic Merkel cell carcinoma of skin
- Neuroendocrine tumor of the skin
- Cell Cancer, Merkel
- Carcinoma, Merkel Cell
- Apudoma of skin (disorder)
- Neuroendocrine neoplasm of liver
- merkel cell cancer
- Merkel cell skin cancer
- Tumors, Merkle
- Liver secondaries
- Secondary malignancy of liver
- Merkel cell carcinoma of unspecified site
- cell merkel tumors
- Merkel cell carcinoma (disorder)
- merkel cell tumor
- Metastatic Merkel cell carcinoma of liver
- carcinoma neuroendocrine skin
- Secondary Merkel cell carcinoma of liver
- MCC
- Apudoma of skin
- Secondary malignant neoplasm of liver
- merkel cell tumour
- Metastatic malignant neoplasm to liver
- Neuroendocrine carcinoma of the skin
- Primary cutaneous neuroendocrine carcinoma
- Metastatic malignant neoplasm of liver
- Metastatic Merkel cell carcinoma to liver
- Liver secondary cancer
- Merkle Tumors
- carcinoma cell merkels
- Neuroendocrine tumour of the skin
- Metastasis to liver
- Anaplastic carcinoma of the skin
- Merkel cell carcinoma (morphologic abnormality)
- Primary small cell carcinoma of the skin
- Merkel cell cancer of the skin
- Metastatic Merkel cell carcinoma to skin
- Secondary Merkel cell carcinoma of skin
- Merkel cell carcinoma NOS
- Cancer metastatic to liver
- Hepatic metastasis
- Cancer, Merkel Cell
- Primary undifferentiated carcinoma of the skin
- Tumor, Merkel Cell
- Cutaneous APUDoma
Common questions
What is the ICD-10-CM code for Merkel cell carcinoma, unspecified?
Merkel cell carcinoma, unspecified is coded as C4A.9 in ICD-10-CM.
What is ICD-10 code C4A.9?
C4A.9 is the ICD-10-CM identifier for Merkel cell carcinoma, unspecified. It is included in the official 2025 release of ICD-10-CM published by CMS and NCHS.
Is C4A.9 a billable code?
Yes, C4A.9 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.9?
C4A.9 sits under C4A (Merkel cell carcinoma) in the ICD-10-CM hierarchy.
What chapter does C4A.9 belong to?
C4A.9 is in Chapter 2: Neoplasms.
What are the synonyms for Merkel cell carcinoma, unspecified?
In clinical text, merkel cell carcinoma, unspecified is also written as: Cancer metastatic to liver, Hepatic metastasis, Liver secondaries, Liver secondary cancer, Merkel cell carcinoma, Merkel cell tumor, and 47 more. Sourced from SNOMED CT, UMLS Metathesaurus, and clinical-terms enrichment.
Why does C4A.9 map to multiple SNOMED CT concepts?
ICD-10-CM is a billing classification with broader categories than SNOMED CT’s clinical terminology. C4A.9 captures the billing-level concept; SNOMED CT splits it into 5 clinical concepts: 1290081007, 14914851000119109, 14914931000119107, 253001006, 94381002.
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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.