What is ICD-10 code C77.8?

C77.8 is the ICD-10-CM diagnosis code for Secondary and unspecified malignant neoplasm of lymph nodes of multiple regions. Cancer that has spread to lymph nodes in multiple different regions of the body, either as a secondary spread from another cancer or when the primary source is unknown. C77.8 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. C77.8 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. C77.8 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. C77.8 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does C77.8 map to under V28?

C77.8 maps to CMS-HCC V28 HCC 17 (Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic). The category numbers, labels, and conditions come from the CMS-HCC V28 model file for payment year 2026.

2026 ICD-10-CM C77.8: Secondary and unspecified

C77.8 maps to CMS-HCC V28 17. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · HCC Buddy coding tools

ICD-10-CM Code View

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Code lookupC77.8

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of ill-defined, other secondary and unspecified sites (C76-C80)

C77.8

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Secondary and unspecified malignant neoplasm of lymph nodes of multiple regions

Cancer that has spread to lymph nodes in multiple different regions of the body, either as a secondary spread from another cancer or when the primary source is unknown.

Buddy Insight

Secondary and unspecified malignant neoplasm of lymph nodes of multiple regions indicates metastatic cancer has spread to lymph node groups in more than one anatomical region.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 17

Cancer Metastatic to Lung, Li...

Code-level coefficient reference

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 008

HHS-HCC 008 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 8

Metastatic Cancer and Acute L...

Code-level coefficient reference

RXHCC

Mapped

HCC 20

Lung, Kidney, and Other Cance...

Code-level coefficient reference

Code Book Path

Official

C77Secondary and unspecified malignant neoplasm of lymph nodes C77.8Secondary and unspecified malignant neoplasm of lymph nodes of multiple regions

Inclusion Terms

Official

No inclusion terms are included in this display for C77.8. Check the code and parent instructions in the Code Book.

Excludes 2

Official

No Excludes 2 notes are included in this display for C77.8. Check the code and parent instructions in the Code Book.

Related Codes

Official

C77.0Secondary and unspecified malignant neoplasm of lymph nodes of head, face and neck C77.1Secondary and unspecified malignant neoplasm of intrathoracic lymph nodes C77.2Secondary and unspecified malignant neoplasm of intra-abdominal lymph nodes C77.3Secondary and unspecified malignant neoplasm of axilla and upper limb lymph nodes C77.4Secondary and unspecified malignant neoplasm of inguinal and lower limb lymph nodes

Includes

Official

No Includes notes are included in this display for C77.8. Check the code and parent instructions in the Code Book.

Excludes 1

Official

malignant neoplasm of lymph nodes, specified as primary (C81-C86, C88, C96.-)Inherited from C77
mesentery metastasis of carcinoid tumor (C7B.04)Inherited from C77
secondary carcinoid tumors of distant lymph nodes (C7B.01)Inherited from C77

Code First

Official

No Code First sequencing instructions are included in this display for C77.8. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for C77.8. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for C77.8. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Documentation specifying which multiple lymph node regions are involved

Consider coding each regional lymph node group separately instead of using this combined code

Pathology or imaging confirming malignant lymphadenopathy in multiple regions

Identification and separate coding of the primary malignancy

MEAT Support

HCC Buddy guidance

Documentation specifying which multiple lymph node regions are involved

Consider coding each regional lymph node group separately instead of using this combined code

Pathology or imaging confirming malignant lymphadenopathy in multiple regions

Identification and separate coding of the primary malignancy

Audit Caution

HCC Buddy guidance

Using this code instead of coding each involved lymph node region separately — individual regional codes provide more clinical detail

Coding multi-region lymphoma as secondary metastatic disease — lymphoma is a primary malignancy

Not coding the primary malignancy alongside this secondary code

Using C77.9 (unspecified) when multiple regions are documented — C77.8 is more specific

Common Mistakes

HCC Buddy guidance

C77.0-C77.5 — Individual regional lymph node codes: Consider coding each region separately for maximum specificity

C77.9 — Secondary malignant neoplasm of lymph node, unspecified: Unspecified region, not multiple regions

C81-C86 — Lymphomas: Primary multi-regional lymph node malignancy, not metastatic disease

C80.0 — Disseminated malignant neoplasm: Widespread disease beyond just lymph nodes

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is C77.8 an HCC code?

Yes. C77.8 (Secondary and unspecified malignant neoplasm of lymph nodes of multiple regions) maps to HCC 17, Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 4.209. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: C77.8 is billable and maps to V28 HCC 17, Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: C77.8
Description: Secondary and unspecified malignant neoplasm of lymph nodes of multiple regions
HCC (V28): HCC 17 — Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic
RAF reference coefficient: 4.209
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 17, Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic

4.209

ESRDHCC 8, Metastatic Cancer and Acute Leukemia

Not separately weighted

RxHCCHCC 20, Lung, Kidney, and Other Cancers; Secondary Cancer of Lymph Nodes and Other Sites

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work C77.8 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for C77.8

For C77.8, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Coder workflow notes

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What This Code Means

C77.8 is the ICD-10-CM diagnosis code for secondary and unspecified malignant neoplasm of lymph nodes of multiple regions. Cancer that has spread to lymph nodes in multiple different regions of the body, either as a secondary spread from another cancer or when the primary source is unknown. C77.8 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of ill-defined, other secondary and unspecified sites (c76-c80).

Under the CMS-HCC V28 risk adjustment model, C77.8 maps to Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic (HCC 17) with a source-labeled community, non-dual, aged reference coefficient of 4.209. No V24 mapping is shown for C77.8; use the applicable model and payment year when reviewing the V28 mapping. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

Use this code only when lymph node involvement is documented in multiple non-contiguous regions; if involvement is in a single region, use the specific regional code. For C77.8, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for C77.8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use this code only when lymph node involvement is documented in multiple non-contiguous regions; if involvement is in a single region, use the specific regional code
•Always attempt to identify and code the primary malignancy separately when possible

Clinical Significance

Secondary and unspecified malignant neoplasm of lymph nodes of multiple regions indicates metastatic cancer has spread to lymph node groups in more than one anatomical region. This represents advanced metastatic disease and is a significant prognostic indicator. When multiple lymph node regions are involved, it often signifies widespread dissemination and impacts staging and treatment decisions profoundly.

Documentation Requirements

✓Documentation specifying which multiple lymph node regions are involved
✓Consider coding each regional lymph node group separately instead of using this combined code
✓Pathology or imaging confirming malignant lymphadenopathy in multiple regions
✓Identification and separate coding of the primary malignancy
✓Staging assessment reflecting multi-regional nodal involvement

Commonly Confused Codes

•C77.0-C77.5: Individual regional lymph node codes: Consider coding each region separately for maximum specificity
•C77.9: Secondary malignant neoplasm of lymph node, unspecified: Unspecified region, not multiple regions
•C81-C86: Lymphomas: Primary multi-regional lymph node malignancy, not metastatic disease
•C80.0: Disseminated malignant neoplasm: Widespread disease beyond just lymph nodes