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C77.1

C77.1Secondary and unspecified malignant neoplasm of intrathoracic lymph nodes

Billable / specific codeICD-10-CM

C77.1 is a billable, specific ICD-10-CM code for secondary and unspecified malignant neoplasm of intrathoracic lymph nodes. It is valid for submission on a claim.

Risk adjustment

C77.1 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:

  • HCC 17 Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic4.209 RAF

Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.

Medicare coverage

C77.1 is named in 41 Medicare coverage policies 41 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A52480Oral Antiemetic Drugs (Replacement for Intravenous Antiemetics) - Policy Article
  • A52986Billing and Coding: Biomarkers for Oncology
  • A53101Billing and Coding: MolDX: bioTheranostics Cancer TYPE ID® Update
  • A54188Billing and Coding: MolDX: bioTheranostics Cancer TYPE ID®

Related codes at this level

Codes that share C77. If C77.1 is not quite right, the correct code is usually one of these.

Questions about C77.1

Is C77.1 a billable ICD-10-CM code?
Yes. C77.1 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does C77.1 sit in the tabular list?
Neoplasms (C00-D49), in the block Malignant neoplasms of ill-defined, other secondary and unspecified sites (C76-C80).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.