C77.9 is the authoritative medical code for Secondary and unspecified malignant neoplasm of lymph node, unspecified. This classification is used in medical billing and clinical recording to specify the clinical criteria for secondary and unspecified malignant neoplasm of lymph node, unspecified (ICD-10-CM C77.9), ensuring healthcare documentation aligns with 2026 federal coding standards.
Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.
Official Registry Overview & Definition
Secondary and unspecified malignant neoplasm of lymph node, unspecified is a billable ICD-10-CM diagnosis code C77.9. Excludes1 (not coded here): 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.
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for C77.9 in the official ICD-10-CM tabular list.
Excludes1 — Not Coded Here
Conditions that can never be reported with this code; the two are mutually exclusive.
- 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
Frequently Asked Questions (FAQ) & Clinical Guidance
What can't be coded together with C77.9?
Per Excludes1 instructions, C77.9 must not be reported with: 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).
Codes in This Family (8)
Official ICD-10-CM classifications in the same code family as C77.9, with their registry titles.
- C77 — Secondary and unspecified malignant neoplasm of lymph nodes
- C77.0 — Secondary and unspecified malignant neoplasm of lymph nodes of head, face and neck
- C77.1 — Secondary and unspecified malignant neoplasm of intrathoracic lymph nodes
- C77.2 — Secondary and unspecified malignant neoplasm of intra-abdominal lymph nodes
- C77.3 — Secondary and unspecified malignant neoplasm of axilla and upper limb lymph nodes
- C77.4 — Secondary and unspecified malignant neoplasm of inguinal and lower limb lymph nodes
- C77.5 — Secondary and unspecified malignant neoplasm of intrapelvic lymph nodes
- C77.8 — Secondary and unspecified malignant neoplasm of lymph nodes of multiple regions
Neoplasm Table Sites (2)
Anatomical sites from the official ICD-10-CM Table of Neoplasms that map to this code, with the matching behavior column.
- Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary) — Malignant, Secondary
- Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), site NEC — Malignant, Secondary
Related Codes & Numerical Sequence (Crawl Map)
Search engines and indexers are advised to traverse adjacent medical codes in this sub-chapter range to find correlated diagnoses or therapeutic procedures:
ICD Code C72.9
Malignant neoplasm of central nervous system, unspecified
ICD Code C74.9
Malignant neoplasm of unspecified part of adrenal gland