C7B.1 Secondary Merkel cell carcinoma

The ICD-10-CM code for Secondary Merkel cell carcinoma is C7B.1 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

2: Neoplasms (C00-D49)

Section

C7B: Secondary neuroendocrine tumors (C7B)

Category C7B

10 codes (8 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to C7B.1:

• Carcinoma (malignant) › secondary › Merkel cell
• Carcinoma (malignant) › Merkel cell › secondary
• Carcinoma (malignant) › Merkel cell › visceral metastatic
• Carcinoma (malignant) › Merkel cell › nodal presentation

Inclusion Terms

• Merkel cell carcinoma nodal presentation
• Merkel cell carcinoma visceral metastatic presentation

U.S. Hospital Utilization

• An estimated 875 U.S. inpatient stays in 2023 included C7B.1 among the documented diagnoses.
• 260 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)