What is ICD-10 code C82.41?

C82.41 is the ICD-10-CM diagnosis code for Follicular lymphoma grade IIIb, lymph nodes of head, face, and neck. A type of cancer of the lymph system (follicular lymphoma) that is grade IIIb and located in the lymph nodes of the head, face, and neck area. C82.41 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. C82.41 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. C82.41 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. C82.41 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 C82.41?

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 C82.41, V28 maps to Lymphoma and Other Cancers at RAF 0.671 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 C82.41?

Verify that lymph node involvement is specifically in the head, face, or neck region as documented Grade IIIb represents a more aggressive form of follicular lymphoma compared to grade IIIa Because C82.41 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.

2026 ICD-10-CM C82.41: Follicular lymphoma grade

ICD-10-CM Code View

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Code lookupC82.41Effective periodFY2026 Apr Update (Apr 1-Sep 30)

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

C82.41

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

Follicular lymphoma grade IIIb, lymph nodes of head, face, and neck

A type of cancer of the lymph system (follicular lymphoma) that is grade IIIb and located in the lymph nodes of the head, face, and neck area.

Buddy Insight

Follicular lymphoma grade IIIb of head, face, and neck lymph nodes represents the most aggressive follicular subtype in a clinically accessible location.

CMS-HCC V28

Mapped

HCC 21

Lymphoma and Other Cancers

RAF 0.671

CMS-HCC V24

Mapped

HCC 10

Lymphoma and Other Cancers

RAF 0.675

ACA/HHS

Mapped

HCC 10

HHS-HCC 10

Varies by metal level

ESRD/PACE

Mapped

HCC 10

Lymphoma and Other Cancers

RAF 0.111

RXHCC

Mapped

HCC 21

Hodgkin Lymphoma and Other Ca...

RAF 0.410

Code Book Path

Official

C82Follicular lymphoma

C82.4Follicular lymphoma grade IIIb

C82.41Follicular lymphoma grade IIIb, lymph nodes of head, face, and neck

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for C82.41 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for C82.41 in this effective period.

Related Child Codes

Official

C82.40Follicular lymphoma grade IIIb, unspecified site

C82.42Follicular lymphoma grade IIIb, intrathoracic lymph nodes

C82.43Follicular lymphoma grade IIIb, intra-abdominal lymph nodes

C82.44Follicular lymphoma grade IIIb, lymph nodes of axilla and upper limb

C82.45Follicular lymphoma grade IIIb, lymph nodes of inguinal region and lower limb

Includes

Official

ICD-10-CM does not list Includes notes for C82.41 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for C82.41 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for C82.41 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for C82.41 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for C82.41 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Pathology confirming grade IIIb pattern (centroblast sheets without centrocytes)

Expert hematopathology distinction from DLBCL documented

Specific head, face, or neck lymph nodes involved

Ann Arbor staging with performance status assessment

MEAT Support

HCC Buddy guidance

Pathology confirming grade IIIb pattern (centroblast sheets without centrocytes)

Expert hematopathology distinction from DLBCL documented

Specific head, face, or neck lymph nodes involved

Ann Arbor staging with performance status assessment

Audit Caution

HCC Buddy guidance

Not distinguishing IIIb from DLBCL — this is one of the most challenging differential diagnoses in lymphoma pathology

Using grade III unspecified when pathology clearly indicates IIIb pattern

Coding Waldeyer ring involvement as head/neck nodal when it is actually extranodal

Not updating code if expert pathology review reclassifies as DLBCL

Common Mistakes

HCC Buddy guidance

C82.31 — Grade IIIa, head/face/neck; IIIa retains centrocytes, IIIb does not

C82.21 — Grade III unspecified, head/face/neck; use C82.41 when IIIb is confirmed

C83.31 — DLBCL, head/face/neck; very similar histologically, requires expert pathology

C82.11 — Grade II, head/face/neck; much lower grade

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 C82.41 an HCC code?

Yes. C82.41 (Follicular lymphoma grade IIIb, lymph nodes of head, face, and neck) maps to Lymphoma and Other Cancers under the CMS-HCC V28 risk adjustment model (and Lymphoma and Other Cancers under V24), with a community non-dual aged RAF of 0.671. It is billable for payment year 2026.

Coder answer: C82.41 is billable and maps to V28 HCC 21, Lymphoma and Other Cancers. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: C82.41
Description: Follicular lymphoma grade IIIb, lymph nodes of head, face, and neck
HCC (V28): HCC 21 — Lymphoma and Other Cancers
RAF: 0.671
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 21, Lymphoma and Other Cancers

0.671

V24HCC 10, Lymphoma and Other Cancers

0.675

ESRDHCC 10, Lymphoma and Other Cancers

0.111

RxHCCHCC 21, Hodgkin Lymphoma and Other Cancers

0.410

Each model's RAF is its CMS base weight for that model's standard population, so 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 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.

Work C82.41 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for C82.41

For C82.41 to 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 C82.41 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

C82.41 is the ICD-10-CM diagnosis code for follicular lymphoma grade iiib, lymph nodes of head, face, and neck. A type of cancer of the lymph system (follicular lymphoma) that is grade IIIb and located in the lymph nodes of the head, face, and neck area. C82.41 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, C82.41 maps to Lymphoma and Other Cancers (HCC 21) with a community, non-dual, aged base RAF weight of 0.671. Under the older V24 model, C82.41 mapped to the same category but with a base RAF weight of 0.675, V28 recalibrated weights across the entire model. 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.

Verify that lymph node involvement is specifically in the head, face, or neck region as documented. Because C82.41 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 C82.41 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify that lymph node involvement is specifically in the head, face, or neck region as documented
•Grade IIIb represents a more aggressive form of follicular lymphoma compared to grade IIIa

Clinical Significance

Follicular lymphoma grade IIIb of head, face, and neck lymph nodes represents the most aggressive follicular subtype in a clinically accessible location. Grade IIIb behaves like diffuse large B-cell lymphoma and is treated with curative-intent chemoimmunotherapy. Head/neck presentation allows for early detection and accessible rebiopsy if transformation is suspected.

Documentation Requirements

✓Pathology confirming grade IIIb pattern (centroblast sheets without centrocytes)
✓Expert hematopathology distinction from DLBCL documented
✓Specific head, face, or neck lymph nodes involved
✓Ann Arbor staging with performance status assessment
✓Curative-intent treatment plan (R-CHOP or equivalent)

Commonly Confused Codes

•C82.31: Grade IIIa, head/face/neck; IIIa retains centrocytes, IIIb does not
•C82.21: Grade III unspecified, head/face/neck; use C82.41 when IIIb is confirmed
•C83.31: DLBCL, head/face/neck; very similar histologically, requires expert pathology
•C82.11: Grade II, head/face/neck; much lower grade