Question 1

What is ICD-10 code C81.00?

Accepted Answer

C81.00 is the ICD-10-CM diagnosis code for Nodular lymphocyte predominant Hodgkin lymphoma, unspecified site. A specific type of Hodgkin lymphoma (blood cancer) characterized by nodular lymphocyte predominance, affecting lymph nodes but the specific location is not documented. It belongs to the ICD-10-CM chapter for neoplasms (c00-d49). C81.00 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. C81.00 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.

Question 2

Is C81.00 an HCC code?

Accepted Answer

Yes. The final FY2026 CMS mapping file maps C81.00 to HCC 21 (Lymphoma and Other Cancers) under CMS-HCC V28 with source-labeled reference coefficients HCC 21 0.671.  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.

Question 3

Is C81.00 billable?

Accepted Answer

Yes. C81.00 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. C81.00 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.

Question 4

Which HCC does C81.00 map to under V28?

Accepted Answer

C81.00 maps to CMS-HCC V28 HCC 21 (Lymphoma and Other Cancers).  The category numbers, labels, and conditions come from the CMS-HCC V28 model file for payment year 2026.

Question 5

What RAF reference is published for C81.00?

Accepted Answer

C81.00 has source-labeled community, non-dual, aged reference coefficients HCC 21 0.671 under CMS-HCC V28 for payment year 2026.  The coefficients come from the CMS V28 relative-factor file. 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.

Question 6

What is the V28 vs V24 difference for C81.00?

Accepted Answer

For C81.00, the current CMS-HCC V28 result is HCC 21 (Lymphoma and Other Cancers). Select a historical effective period before comparing a V24 mapping.  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.

Question 7

What documentation supports C81.00?

Accepted Answer

If lymph node location is documented, use a more specific code (C81.01-C81.09) rather than C81.00 Verify pathology report confirms nodular lymphocyte predominant subtype For C81.00, 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. See the MEAT criteria checklist at /meat-criteria for what Monitor, Evaluate, Assess, or Treat looks like in a note. One mnemonic element does not establish that a diagnosis is reportable.

Question 8

Can C81.00 be a primary diagnosis?

Accepted Answer

Yes. C81.00 carries no code-first instruction in the FY2026 tabular, so it can be the first-listed diagnosis when it is the condition chiefly responsible for the encounter and the note supports it, and it can also be reported as a secondary diagnosis. For risk adjustment the order does not matter; the V28 category is the same either way.

Question 9

Which codes cannot be reported with C81.00?

Accepted Answer

The Excludes1 note that applies to C81.00 lists personal history of Hodgkin lymphoma (Z85.71). An Excludes1 condition is not reported together with C81.00; report one or the other, unless the two conditions are unrelated, which the ICD-10-CM Official Guidelines (Section I.A.12.a) allow. The Excludes2 note lists Kaposi's sarcoma of lymph nodes (C46.3); secondary and unspecified neoplasm of lymph nodes (C77.-); secondary neoplasm of bone marrow (C79.52); secondary neoplasm of spleen (C78.89); those are separate conditions that may be reported together with C81.00 when both are documented.

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C81.00

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C81.00 ICD-10-CM Code: Nodular lymphocyte predominant Hodgkin lymphoma, unspecified site

HCC Buddy Code Card

C81.00

Is C81.00 an HCC code?

HCC Category Mapping

MEAT review for C81.00

Get the V28 mapping + MEAT cheat sheet

What This Code Means

Coding Tips

Clinical Significance

Documentation Requirements

Commonly Confused Codes

Child Codes

Code Hierarchy

Also searched as

Work C81.00 in HCC Buddy