What is ICD-10 code C81.79?

C81.79 is the ICD-10-CM diagnosis code for Other Hodgkin lymphoma, extranodal and solid organ sites. A type of Hodgkin lymphoma that has spread to organs outside the lymph node system, such as the liver, lungs, or bone. It belongs to the ICD-10-CM chapter for neoplasms (c00-d49). C81.79 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. C81.79 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. C81.79 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. C81.79 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.

What is the V28 vs V24 difference for C81.79?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For C81.79, V28 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors at RAF 0.545 while V24 mapped to Lymphoma and Other Cancers at RAF 0.675. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting C81.79?

Document the specific extranodal site(s) involved in the medical record for clinical clarity This code indicates more advanced disease; verify staging information is documented Because C81.79 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

C81.79 ICD-10 Code: Other Hodgkin lymphoma

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupC81.79Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of lymphoid, hematopoietic and related tissue (C81-C96)

C81.79

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

Other Hodgkin lymphoma, extranodal and solid organ sites

A type of Hodgkin lymphoma that has spread to organs outside the lymph node system, such as the liver, lungs, or bone.

Buddy Insight

Other Hodgkin lymphoma with extranodal and solid organ involvement represents stage IV disease from an uncommon histologic variant.

CMS-HCC V28

Mapped

HCC 21

Breast, Prostate, Colorectal ...

RAF 0.545

CMS-HCC V24

Mapped

HCC 10

Lymphoma and Other Cancers

RAF 0.675

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 10

Lymphoma and Other Cancers

RAF 0.0

RXHCC

Mapped

HCC 21

Hodgkin Lymphoma and Other Ca...

RAF 0.0

Code Trumping

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Code Book Path

Official

C81Hodgkin lymphoma

C81.7Other Hodgkin lymphoma

C81.79Other Hodgkin lymphoma, extranodal and solid organ sites

Inclusion Terms

Official

Classical Hodgkin lymphoma NOS
Other classical Hodgkin lymphoma

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for C81.79 in this effective period.

Related Child Codes

Official

C81.70Other Hodgkin lymphoma, unspecified site

C81.71Other Hodgkin lymphoma, lymph nodes of head, face, and neck

C81.72Other Hodgkin lymphoma, intrathoracic lymph nodes

C81.73Other Hodgkin lymphoma, intra-abdominal lymph nodes

C81.74Other Hodgkin lymphoma, lymph nodes of axilla and upper limb

Includes

Official

ICD-10-CM does not list Includes notes for C81.79 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for C81.79 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for C81.79 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for C81.79 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for C81.79 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Pathology confirming Hodgkin lymphoma classified as 'other' subtype

Documentation of specific extranodal organ(s) involved with imaging or biopsy confirmation

Stage IV designation reflecting organ involvement

Bone marrow biopsy results if marrow involvement is suspected

MEAT Support

HCC Buddy guidance

Pathology confirming Hodgkin lymphoma classified as 'other' subtype

Documentation of specific extranodal organ(s) involved with imaging or biopsy confirmation

Stage IV designation reflecting organ involvement

Bone marrow biopsy results if marrow involvement is suspected

Audit Caution

HCC Buddy guidance

Using secondary malignancy codes for lymphoma spread to organs — all lymphoma involvement is coded as primary

Coding C81.79 for isolated splenic disease when C81.77 is the specific code

Not documenting the specific organs involved, which reduces clinical value of the code

Failing to capture bone marrow involvement which has staging implications

Common Mistakes

HCC Buddy guidance

C81.77 — Other Hodgkin lymphoma, spleen: use C81.77 specifically for splenic disease; C81.79 covers other extranodal organs

C81.78 — Other Hodgkin lymphoma, multiple lymph node sites: C81.78 is for multi-site nodal disease; C81.79 is for organ involvement

C78-C79 — Secondary malignant neoplasm codes: lymphoma organ involvement is coded as primary lymphoma, not secondary neoplasm

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is C81.79 an HCC code?

Yes. C81.79 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors under the CMS-HCC V28 risk adjustment model (and Lymphoma and Other Cancers under V24).

HCC Category Mapping

V28HCC 21, Breast, Prostate, Colorectal and Other Cancers and Tumors

0.545

V24HCC 10, Lymphoma and Other Cancers

0.675

ESRDHCC 10, Lymphoma and Other Cancers

0.000

RxHCCHCC 21, Hodgkin Lymphoma and Other Cancers

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

MEAT Criteria for C81.79

For C81.79to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

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

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed C81.79 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

C81.79 is the ICD-10-CM diagnosis code for other hodgkin lymphoma, extranodal and solid organ sites. A type of Hodgkin lymphoma that has spread to organs outside the lymph node system, such as the liver, lungs, or bone. C81.79 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of lymphoid, hematopoietic and related tissue (c81-c96).

Under the CMS-HCC V28 risk adjustment model, C81.79 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors (HCC 21) with a community, non-dual, aged base RAF weight of 0.545. Under the older CMS-HCC V24 model, C81.79 maps to Lymphoma and Other Cancers (HCC 10) with a community, non-dual, aged base RAF weight of 0.675. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Document the specific extranodal site(s) involved in the medical record for clinical clarity. Because C81.79 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. 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, RAF weights, and MEAT documentation criteria for C81.79 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Document the specific extranodal site(s) involved in the medical record for clinical clarity
•This code indicates more advanced disease; verify staging information is documented

Clinical Significance

Other Hodgkin lymphoma with extranodal and solid organ involvement represents stage IV disease from an uncommon histologic variant. Organ involvement such as liver, lung, bone, or bone marrow significantly impacts prognosis and drives intensive systemic treatment. The 'other' subtype designation may prompt expert pathology consultation to better characterize the variant for treatment optimization.

Documentation Requirements

✓Pathology confirming Hodgkin lymphoma classified as 'other' subtype
✓Documentation of specific extranodal organ(s) involved with imaging or biopsy confirmation
✓Stage IV designation reflecting organ involvement
✓Bone marrow biopsy results if marrow involvement is suspected
✓Active treatment documentation and encounter-specific assessment

Commonly Confused Codes

•C81.77 — Other Hodgkin lymphoma, spleen: use C81.77 specifically for splenic disease; C81.79 covers other extranodal organs
•C81.78 — Other Hodgkin lymphoma, multiple lymph node sites: C81.78 is for multi-site nodal disease; C81.79 is for organ involvement
•C78-C79 — Secondary malignant neoplasm codes: lymphoma organ involvement is coded as primary lymphoma, not secondary neoplasm