What is ICD-10 code C82.66?

C82.66 is the ICD-10-CM diagnosis code for Cutaneous follicle center lymphoma, intrapelvic lymph nodes. A type of non-Hodgkin lymphoma affecting the skin and follicle center cells in the lymph nodes within the pelvis. It belongs to the ICD-10-CM chapter for neoplasms (c00-d49). C82.66 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. C82.66 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. C82.66 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. C82.66 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 C82.66?

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 C82.66, 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 C82.66?

Verify intrapelvic (within pelvis) lymph node involvement is clearly documented Distinguish from other pelvic lymphomas by confirming cutaneous follicle center origin Because C82.66 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 C82.66: Cutaneous follicle center

ICD-10-CM Code View

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Code lookupC82.66Effective periodFY2026 Apr Update (Apr 1-Sep 30)

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

C82.66

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

Cutaneous follicle center lymphoma, intrapelvic lymph nodes

A type of non-Hodgkin lymphoma affecting the skin and follicle center cells in the lymph nodes within the pelvis.

Buddy Insight

Cutaneous follicle center lymphoma involving intrapelvic lymph nodes represents a deeper spread pattern that is atypical for a primary cutaneous lymphoma.

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

C82.6Cutaneous follicle center lymphoma

C82.66Cutaneous follicle center lymphoma, intrapelvic lymph nodes

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for C82.66 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for C82.66 in this effective period.

Related Child Codes

Official

C82.60Cutaneous follicle center lymphoma, unspecified site

C82.61Cutaneous follicle center lymphoma, lymph nodes of head, face, and neck

C82.62Cutaneous follicle center lymphoma, intrathoracic lymph nodes

C82.63Cutaneous follicle center lymphoma, intra-abdominal lymph nodes

C82.64Cutaneous follicle center lymphoma, lymph nodes of axilla and upper limb

Includes

Official

ICD-10-CM does not list Includes notes for C82.66 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for C82.66 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for C82.66 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for C82.66 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for C82.66 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Skin biopsy confirming cutaneous follicle center lymphoma origin

Cross-sectional imaging documenting intrapelvic lymph node involvement

Clinical justification for maintaining primary cutaneous classification

Distinction between intrapelvic and inguinal lymph node groups on imaging

MEAT Support

HCC Buddy guidance

Skin biopsy confirming cutaneous follicle center lymphoma origin

Cross-sectional imaging documenting intrapelvic lymph node involvement

Clinical justification for maintaining primary cutaneous classification

Distinction between intrapelvic and inguinal lymph node groups on imaging

Audit Caution

HCC Buddy guidance

Confusing intrapelvic with inguinal lymph nodes — these require different site codes

Not reassessing the cutaneous primary diagnosis when deep pelvic nodes are involved

Using this code without cross-sectional imaging confirmation of intrapelvic (not inguinal) location

Failing to consider upgrading to systemic follicular lymphoma classification when deep nodal disease is found

Common Mistakes

HCC Buddy guidance

C82.65 — Cutaneous follicle center lymphoma, lymph nodes of inguinal region and lower limb: Inguinal nodes are superficial; intrapelvic (iliac) nodes are deep

C82.56 — Diffuse follicle center lymphoma, intrapelvic lymph nodes: Systemic disease without cutaneous origin

C82.86 — Other types of follicular lymphoma, intrapelvic lymph nodes: Different follicular subtype

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 C82.66 an HCC code?

Yes. C82.66 (Cutaneous follicle center lymphoma, intrapelvic lymph nodes) 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: C82.66 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: C82.66
Description: Cutaneous follicle center lymphoma, intrapelvic lymph nodes
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 C82.66 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for C82.66

For C82.66 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 C82.66 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

C82.66 is the ICD-10-CM diagnosis code for cutaneous follicle center lymphoma, intrapelvic lymph nodes. A type of non-Hodgkin lymphoma affecting the skin and follicle center cells in the lymph nodes within the pelvis. C82.66 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, C82.66 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, C82.66 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 intrapelvic (within pelvis) lymph node involvement is clearly documented. Because C82.66 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 C82.66 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify intrapelvic (within pelvis) lymph node involvement is clearly documented
•Distinguish from other pelvic lymphomas by confirming cutaneous follicle center origin

Clinical Significance

Cutaneous follicle center lymphoma involving intrapelvic lymph nodes represents a deeper spread pattern that is atypical for a primary cutaneous lymphoma. Intrapelvic nodal involvement (iliac, obturator, presacral nodes) suggests the disease may have extended beyond typical regional drainage and should prompt reconsideration of whether the primary cutaneous designation is accurate. Clinical staging and multidisciplinary discussion may be warranted.

Documentation Requirements

✓Skin biopsy confirming cutaneous follicle center lymphoma origin
✓Cross-sectional imaging documenting intrapelvic lymph node involvement
✓Clinical justification for maintaining primary cutaneous classification
✓Distinction between intrapelvic and inguinal lymph node groups on imaging
✓Complete staging including assessment of other nodal and extranodal sites

Commonly Confused Codes

•C82.65: Cutaneous follicle center lymphoma, lymph nodes of inguinal region and lower limb: Inguinal nodes are superficial; intrapelvic (iliac) nodes are deep
•C82.56: Diffuse follicle center lymphoma, intrapelvic lymph nodes: Systemic disease without cutaneous origin
•C82.86: Other types of follicular lymphoma, intrapelvic lymph nodes: Different follicular subtype