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C77.4 ICD-10-CM Code: Secondary and unspecified malignant neoplasm of inguinal and lower limb lymph nodes

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
3 Excludes1
Risk adjustment
CMS-HCC V28: 1 category · CMS-HCC V22 category 8 · RxHCC V08 category 20

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v44, Appendix B.

  • MS-DRG 820 — LYMPHOMA AND LEUKEMIA WITH MAJOR O.R. PROCEDURES WITH MCC (MDC 17)
  • MS-DRG 821 — LYMPHOMA AND LEUKEMIA WITH MAJOR O.R. PROCEDURES WITH CC (MDC 17)
  • MS-DRG 822 — LYMPHOMA AND LEUKEMIA WITH MAJOR O.R. PROCEDURES WITHOUT CC/MCC (MDC 17)
  • MS-DRG 823 — LYMPHOMA AND NON-ACUTE LEUKEMIA WITH OTHER PROCEDURES WITH MCC (MDC 17)
  • MS-DRG 824 — LYMPHOMA AND NON-ACUTE LEUKEMIA WITH OTHER PROCEDURES WITH CC (MDC 17)
  • MS-DRG 825 — LYMPHOMA AND NON-ACUTE LEUKEMIA WITH OTHER PROCEDURES WITHOUT CC/MCC (MDC 17)
  • MS-DRG 840 — LYMPHOMA AND NON-ACUTE LEUKEMIA WITH MCC (MDC 17)
  • MS-DRG 841 — LYMPHOMA AND NON-ACUTE LEUKEMIA WITH CC (MDC 17)
  • MS-DRG 842 — LYMPHOMA AND NON-ACUTE LEUKEMIA WITHOUT CC/MCC (MDC 17)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Risk Adjustment (CMS-HCC)

Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.

  • HCC 18 — Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid (supersedes HCC 19, HCC 20, HCC 21, HCC 22, HCC 23)

Other models: CMS-HCC V22 HCC 8 · RxHCC V08 HCC 20

Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for C77.4 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Notes without a marker are published on C77.4 itself; “inherited from” names the category or block whose note applies here.

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from C77

Coder workflow for C77.4

MedCoder structured workflow — derived from this code’s own official record

Before you code C77.4

  1. Unspecified does not mean incorrect. When the record gives no greater specificity, C77.4 may be the appropriate code. Check the record for detail that supports a more specific sibling. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

    See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

  2. Confirm the documented site and behavior (this code’s block classifies malignant neoplasms), whether the site is primary or secondary, and whether the malignancy is current or a personal history: a previously excised malignancy with no further treatment and no evidence of disease is history, not current disease. Verify the site against the Table of Neoplasms. Neoplasm chapter guidelines (Guidelines I.C.2.a, I.C.2.d, I.C.2.m).

    See the Table of Neoplasms entries · Guide: Active cancer vs history of cancer →

  3. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with C77.4. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the record document the detail a more specific sibling code needs?
    Yes → Review the specific siblings in this subcategory.
    No → Continue — C77.4 is appropriate when the documentation goes no further.
  2. Does the documentation support a condition named in C77.4’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewC88, C96, C7B.04, C7B.01

Consider C77.4. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Anatomical site
At the most specific level the record states; a site the classification separates cannot be assumed from a procedure or a measurement.
Behavior and current-versus-history status
Malignant, in situ, benign or uncertain; primary or secondary; current disease or personal history (Guidelines I.C.2.m).
Any detail beyond this code’s title
What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

  • Excludes1 — check before selecting C77.4(3 notes)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with C77.4: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareC88, C96, C7B.04, C7B.01

    See the official tabular notes · Guidelines I.A.12.a

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: The provider documents the condition in the terms of this code’s title and records no further detail.

Coding question: Is a more specific sibling code supportable?

Path: Review the subcategory for a sibling that names the missing detail.

Reason: A more specific code needs documentation of the distinguishing element; without it the unspecified code is appropriate, and a provider query is the route to specificity (Guidelines I.A.9.b, I.B.18).

Documentation: Both the condition C77.4 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewC88, C96, C7B.04, C7B.01

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Don’t confuse C77.4 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of C77.4 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • C81— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of malignant neoplasm of lymph nodes, specified as primary moves the case to C81; the two are not reported together unless documented as unrelated.

    Full comparison: C77.4 vs C81 →

  • C86— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of malignant neoplasm of lymph nodes, specified as primary moves the case to C86; the two are not reported together unless documented as unrelated.

    Full comparison: C77.4 vs C86 →

  • C88— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of malignant neoplasm of lymph nodes, specified as primary moves the case to C88; the two are not reported together unless documented as unrelated.

    Full comparison: C77.4 vs C88 →

  • C96— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of malignant neoplasm of lymph nodes, specified as primary moves the case to C96; the two are not reported together unless documented as unrelated.

    Full comparison: C77.4 vs C96 →

  • C7B.04— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of mesentery metastasis of carcinoid tumor moves the case to C7B.04; the two are not reported together unless documented as unrelated.

    Full comparison: C77.4 vs C7B.04 →

  • C7B.01— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of secondary carcinoid tumors of distant lymph nodes moves the case to C7B.01; the two are not reported together unless documented as unrelated.

    Full comparison: C77.4 vs C7B.01 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Code Overview

Secondary and unspecified malignant neoplasm of inguinal and lower limb lymph nodes is a billable ICD-10-CM diagnosis code (C77.4).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Neoplasm Table Sites (11)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

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), Cloquet — Malignant, Secondary
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), femoral — Malignant, Secondary
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), groin — Malignant, Secondary
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), inguina, inguinal — Malignant, Secondary
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), leg — Malignant, Secondary
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), limb, lower — Malignant, Secondary
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), lower limb — Malignant, Secondary
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), popliteal — Malignant, Secondary
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), Rosenmuller's — Malignant, Secondary
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), subinguinal — Malignant, Secondary
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), tibial — Malignant, Secondary

Verify Before Coding

  • CC as a secondary diagnosis (FY2027). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name C77.4 or its code family, from the CMS ICD-10-CM tabular instructional notes and the CMS Table of Neoplasms. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 15 Excludes2 notes: C81 — Hodgkin lymphoma (via C77.-), C81-C96 — Malignant neoplasms of lymphoid, hematopoietic and related tissue (C81-C96) (via C77.-), C82 — Follicular lymphoma (via C77.-), C83 — Non-follicular lymphoma (via C77.-), C84 — Mature T/NK-cell lymphomas (via C77.-), C85 — Other specified and unspecified types of non-Hodgkin lymphoma (via C77.-), C86 — Other specified types of T/NK-cell lymphoma (via C77.-), C88 — Malignant immunoproliferative diseases and certain other B-cell lymphomas (via C77.-), C90 — Multiple myeloma and malignant plasma cell neoplasms (via C77.-), C91 — Lymphoid leukemia (via C77.-), C92 — Myeloid leukemia (via C77.-), C93 — Monocytic leukemia (via C77.-), C94 — Other leukemias of specified cell type (via C77.-), C95 — Leukemia of unspecified cell type (via C77.-), C96 — Other and unspecified malignant neoplasms of lymphoid, hematopoietic and related tissue (via C77.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

Referenced by 3 Same-site neoplasm codes: D36.0 — Benign neoplasm of lymph nodesCompare C77.4 vs D36.0 →, D48.7 — Neoplasm of uncertain behavior of other specified sitesCompare C77.4 vs D48.7 →, D49.89 — Neoplasm of unspecified behavior of other specified sitesCompare C77.4 vs D49.89 →.

These codes represent related neoplasm behaviors affecting the same anatomic site.

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 24 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 9 MS-DRGs: DRG 820 (MDC 17), DRG 821 (MDC 17), DRG 822 (MDC 17), DRG 823 (MDC 17), DRG 824 (MDC 17), DRG 825 (MDC 17), DRG 840 (MDC 17), DRG 841 (MDC 17), DRG 842 (MDC 17).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):NEO070 — Secondary malignancies (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

C45.7 — Mesothelioma of other sites, C45.9 — Mesothelioma, unspecified, C46.3 — Kaposi's sarcoma of lymph nodes, C76.8 — Malignant neoplasm of other specified ill-defined sites, 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, C77.5 — Secondary and unspecified malignant neoplasm of intrapelvic lymph nodes, C77.8 — Secondary and unspecified malignant neoplasm of lymph nodes of multiple regions, C77.9 — Secondary and unspecified malignant neoplasm of lymph node, unspecified, C7A.00 — Malignant carcinoid tumor of unspecified site, C7A.098 — Malignant carcinoid tumors of other sites, C7A.1 — Malignant poorly differentiated neuroendocrine tumors, C7A.8 — Other malignant neuroendocrine tumors, C7B.00 — Secondary carcinoid tumors, unspecified site, C7B.01 — Secondary carcinoid tumors of distant lymph nodes, C7B.1 — Secondary Merkel cell carcinoma, C80.0 — Disseminated malignant neoplasm, unspecified, C80.1 — Malignant (primary) neoplasm, unspecified, +3 more

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid) for risk-adjusted payment.

C77.0 — Secondary and unspecified malignant neoplasm of lymph nodes of head, face and neck, C77.2 — Secondary and unspecified malignant neoplasm of intra-abdominal lymph nodes, C77.5 — Secondary and unspecified malignant neoplasm of intrapelvic lymph nodes, C77.9 — Secondary and unspecified malignant neoplasm of lymph node, unspecified, C79.10 — Secondary malignant neoplasm of unspecified urinary organs, C79.11 — Secondary malignant neoplasm of bladder, C79.19 — Secondary malignant neoplasm of other urinary organs, C79.2 — Secondary malignant neoplasm of skin, C79.51 — Secondary malignant neoplasm of bone, C79.52 — Secondary malignant neoplasm of bone marrow, C79.60 — Secondary malignant neoplasm of unspecified ovary, C79.61 — Secondary malignant neoplasm of right ovary, C79.62 — Secondary malignant neoplasm of left ovary, C79.63 — Secondary malignant neoplasm of bilateral ovaries, C79.81 — Secondary malignant neoplasm of breast, C79.82 — Secondary malignant neoplasm of genital organs, C79.89 — Secondary malignant neoplasm of other specified sites, C79.9 — Secondary malignant neoplasm of unspecified site, C80.0 — Disseminated malignant neoplasm, unspecified, C91.00 — Acute lymphoblastic leukemia not having achieved remission, +5 more

Related risk categories

These categories interact through CMS's HCC hierarchy — one can suppress the other's risk-adjustment weight when both are present on a claim.

Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic, Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers, Lung and Other Severe Cancers, Lymphoma and Other Cancers, Bladder, Colorectal, and Other Cancers, Prostate, Breast, and Other Cancers and Tumors

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Secondary malignancies).

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, C77.5 — Secondary and unspecified malignant neoplasm of intrapelvic lymph nodes, C77.8 — Secondary and unspecified malignant neoplasm of lymph nodes of multiple regions, C77.9 — Secondary and unspecified malignant neoplasm of lymph node, unspecified, C78.00 — Secondary malignant neoplasm of unspecified lung, C78.01 — Secondary malignant neoplasm of right lung, C78.02 — Secondary malignant neoplasm of left lung, C78.1 — Secondary malignant neoplasm of mediastinum, C78.2 — Secondary malignant neoplasm of pleura, C78.30 — Secondary malignant neoplasm of unspecified respiratory organ, C78.39 — Secondary malignant neoplasm of other respiratory organs, C78.4 — Secondary malignant neoplasm of small intestine, C78.5 — Secondary malignant neoplasm of large intestine and rectum, C78.6 — Secondary malignant neoplasm of retroperitoneum and peritoneum, C78.7 — Secondary malignant neoplasm of liver and intrahepatic bile duct, C78.80 — Secondary malignant neoplasm of unspecified digestive organ, C78.89 — Secondary malignant neoplasm of other digestive organs, +24 more

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Iron Panel, Prostate-Specific Antigen (PSA)

Contextual Map

Every relationship of C77.4 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run C77.4 with these 8 related codes in Claim Check

Hierarchy

Same site

Referenced by Excludes2 notes (15)

Referenced by Same-site neoplasm codes

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

  • HCC 18 — Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid [CMS-HCC]: “Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid — supersedes HCC 19 (Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers), HCC 20 (Lung and Other Severe Cancers), HCC 21 (Lymphoma and Other Cancers), HCC 22 (Bladder, Colorectal, and Other Cancers), HCC 23 (Prostate, Breast, and Other Cancers and Tumors)”— CMS-HCC V28 · 2026

MS-DRG Grouper (9)

MDC crossing

  • MDC 17 — Myeloproliferative Diseases and Disorders, Poorly Differentiated Neoplasms[MDC crossing]: “Myeloproliferative Diseases and Disorders, Poorly Differentiated Neoplasms — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 4,735 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Neoplasm sites (11)

  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), Cloquet — Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), Cloquet — Malignant, Secondary [Neoplasm table]: “Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), Cloquet (Malignant, Secondary)”— CMS Table of Neoplasms · icd10cm-fy2026
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), femoral — Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), femoral — Malignant, Secondary [Neoplasm table]: “Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), femoral (Malignant, Secondary)”— CMS Table of Neoplasms · icd10cm-fy2026
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), groin — Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), groin — Malignant, Secondary [Neoplasm table]: “Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), groin (Malignant, Secondary)”— CMS Table of Neoplasms · icd10cm-fy2026
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), inguina, inguinal — Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), inguina, inguinal — Malignant, Secondary [Neoplasm table]: “Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), inguina, inguinal (Malignant, Secondary)”— CMS Table of Neoplasms · icd10cm-fy2026
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), leg — Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), leg — Malignant, Secondary [Neoplasm table]: “Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), leg (Malignant, Secondary)”— CMS Table of Neoplasms · icd10cm-fy2026
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), limb, lower — Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), limb, lower — Malignant, Secondary [Neoplasm table]: “Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), limb, lower (Malignant, Secondary)”— CMS Table of Neoplasms · icd10cm-fy2026
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), lower limb — Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), lower limb — Malignant, Secondary [Neoplasm table]: “Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), lower limb (Malignant, Secondary)”— CMS Table of Neoplasms · icd10cm-fy2026
  • Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), popliteal — Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), popliteal — Malignant, Secondary [Neoplasm table]: “Neoplasm, neoplastic, lymph, lymphatic channel NEC, gland (secondary), popliteal (Malignant, Secondary)”— CMS Table of Neoplasms · icd10cm-fy2026
  • and 3 more

Nearest codes

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v44 Release, file and checksum · Publisher’s page
Risk adjustment Official source data
2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "C77.4 — Secondary and unspecified malignant neoplasm of inguinal and lower limb lymph nodes." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/c77.4-secondary-and-unspecified-malignant-neoplasm-of-inguinal-and-lower-limb-lymph-nodes

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Secondary and unspecified malignant neoplasm of inguinal and lower limb lymph nodes

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to C77.4 in its code family, with their registry titles.

View all codes in the C77 family