When is ICD-10 code C77 used?

Doctors, hospitals, and insurers may use ICD-10 code C77 when recording secondary and unspecified malignant neoplasm of lymph nodes in a standardized format. This entry may also act as a broader category that points toward more specific child codes.

Does ICD-10 code C77 confirm a diagnosis?

No. A code helps standardize documentation and claims, but it should not be read as a substitute for a clinician's full assessment.

ICD10

ICD-10 Code C77: Secondary and unspecified malignant neoplasm of lymph nodes

Name: ICD-10 Code C77: Secondary and unspecified malignant neoplasm of lymph nodes
Creator: HealthAssure Clinical Team
Published: 2026-05-21T06:02:43.962Z

C77 is an ICD-10 diagnosis entry used to group records related to Secondary and unspecified malignant neoplasm of lymph nodes. You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen. ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Neoplasms (C00-D49).

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Neoplasms (C00-D49).

When is it used?

May be used when a clinician documents secondary and unspecified malignant neoplasm of lymph nodes in a patient's medical record.
May appear in hospital records, claims, referrals, and clinical documentation.
This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.

What it does not mean

A code alone does not explain severity, treatment plan, or outcome.
A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
This entry may represent a broader category rather than the most specific billable code.

Code hierarchy

chapter

2Neoplasms (C00-D49)

block

C00-C96Malignant neoplasms

block

C76-C80Malignant neoplasms of ill-defined, other secondary and unspecified sites

currentC76-C80

Official coding notes

Excludes1 (do not code together)

malignant neoplasm of lymph nodes, specified as primary (C81-C86, C88, C96.-)
mesentery metastasis of carcinoid tumor (C7B.04)
secondary carcinoid tumors of distant lymph nodes (C7B.01)

Where you may see this code

You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.

Related specialists

OncologistGeneral Physician

Sibling codes

C7AMalignant neuroendocrine tumors (C7A)C7BSecondary neuroendocrine tumors (C7B)

Coding guidelines

Compatibility

Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.

Legacy codes

C77

Replacement codes

C77.0 — Secondary and unspecified malignant neoplasm of lymph nodes of head, face and neckC77.1 — Secondary and unspecified malignant neoplasm of intrathoracic lymph nodesC77.2 — Secondary and unspecified malignant neoplasm of intra-abdominal lymph nodesC77.3 — Secondary and unspecified malignant neoplasm of axilla and upper limb lymph nodesC77.4 — Secondary and unspecified malignant neoplasm of inguinal and lower limb lymph nodesC77.5 — Secondary and unspecified malignant neoplasm of intrapelvic lymph nodesC77.8 — Secondary and unspecified malignant neoplasm of lymph nodes of multiple regionsC77.9 — Secondary and unspecified malignant neoplasm of lymph node, unspecified

Common synonyms

Secondary and unspecified malignant neoplasm of lymph nodesSecondary and malignant neoplasm of lymph nodes

Frequently asked questions

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.