What is ICD-10 code C82.52?

C82.52 is the ICD-10-CM diagnosis code for Diffuse follicle center lymphoma, intrathoracic lymph nodes. A type of cancer of the lymph system (diffuse follicle center lymphoma) located in the lymph nodes within the chest cavity. It belongs to the ICD-10-CM chapter for neoplasms (c00-d49). C82.52 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. C82.52 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. C82.52 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. C82.52 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.

Which HCC does C82.52 map to under V28?

C82.52 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.

What documentation supports C82.52?

Intrathoracic involvement should be confirmed by chest imaging; document whether mediastinal or hilar nodes are affected Chest involvement may cause respiratory symptoms; note any associated complications in documentation Because C82.52 maps to an HCC category, the documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) before the diagnosis is used for risk adjustment. See the MEAT criteria checklist at /meat-criteria for what Monitor, Evaluate, Assess, or Treat looks like in a note. MEAT is generic documentation evidence, not a payer-specific rule.

2026 ICD-10-CM C82.52: Diffuse follicle center

C82.52 maps to CMS-HCC V28 21. A source-labeled RAF reference is available. Documentation must support MEAT. MEAT criteria · RAF Calculator · HCC coding software

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Code lookupC82.52Effective periodFY2026 Apr Update (Apr 1-Sep 30)

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

C82.52

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

Diffuse follicle center lymphoma, intrathoracic lymph nodes

A type of cancer of the lymph system (diffuse follicle center lymphoma) located in the lymph nodes within the chest cavity.

Buddy Insight

CMS-HCC V28

Mapped

HCC 21

Lymphoma and Other Cancers

Code-level coefficient reference

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 010

HHS-HCC 010 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 10

Lymphoma and Other Cancers

Code-level coefficient reference

RXHCC

Mapped

HCC 21

Lymphomas and Other Hematolog...

Code-level coefficient reference

Code Book Path

Official

C82Follicular lymphoma

C82.5Diffuse follicle center lymphoma

C82.52Diffuse follicle center lymphoma, intrathoracic lymph nodes

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for C82.52 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for C82.52 in this effective period.

Related Child Codes

Official

C82.50Diffuse follicle center lymphoma, unspecified site

C82.51Diffuse follicle center lymphoma, lymph nodes of head, face, and neck

C82.53Diffuse follicle center lymphoma, intra-abdominal lymph nodes

C82.54Diffuse follicle center lymphoma, lymph nodes of axilla and upper limb

C82.55Diffuse follicle center lymphoma, lymph nodes of inguinal region and lower limb

Includes

Official

ICD-10-CM does not list Includes notes for C82.52 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for C82.52 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for C82.52 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for C82.52 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for C82.52 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Pathology confirming diffuse follicle center lymphoma

Chest CT or PET/CT documenting intrathoracic lymph node involvement with measurements

Specification of which intrathoracic nodes are involved (mediastinal, hilar, paratracheal, etc.)

Assessment for compressive complications (airway, vascular, esophageal)

MEAT Support

HCC Buddy guidance

Pathology confirming diffuse follicle center lymphoma

Chest CT or PET/CT documenting intrathoracic lymph node involvement with measurements

Specification of which intrathoracic nodes are involved (mediastinal, hilar, paratracheal, etc.)

Assessment for compressive complications (airway, vascular, esophageal)

Audit Caution

HCC Buddy guidance

Coding intrathoracic site when imaging shows hilar adenopathy that may actually represent intra-abdominal extension across the diaphragm

Using this code for pulmonary parenchymal involvement rather than lymph node involvement — parenchymal disease is extranodal (C82.59)

Failing to capture pleural effusion or other thoracic complications as additional codes when present

Not distinguishing mediastinal lymphadenopathy from primary mediastinal B-cell lymphoma which is a separate entity

Common Mistakes

HCC Buddy guidance

C82.62 — Cutaneous follicle center lymphoma, intrathoracic lymph nodes: Cutaneous variant originates in skin; verify the primary lymphoma type

C82.82 — Other types of follicular lymphoma, intrathoracic lymph nodes: Use C82.52 when diffuse follicle center type is confirmed

C85.22 — Mediastinal (thymic) large B-cell lymphoma, intrathoracic: This is a distinct entity from diffuse follicle center lymphoma

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 C82.52 an HCC code?

Yes. C82.52 (Diffuse follicle center lymphoma, intrathoracic lymph nodes) maps to HCC 21, Lymphoma and Other Cancers under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 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. It is billable for payment year 2026.

Coder answer: C82.52 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: C82.52
Description: Diffuse follicle center lymphoma, intrathoracic lymph nodes
HCC (V28): HCC 21 — Lymphoma and Other Cancers
RAF reference coefficient: 0.671
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 21, Lymphoma and Other Cancers

0.671

ESRDHCC 10, Lymphoma and Other Cancers

Not separately weighted

RxHCCHCC 21, Lymphomas and Other Hematologic Cancers

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. 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 context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work C82.52 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT Criteria for C82.52

For C82.52 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 C82.52 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

C82.52 is the ICD-10-CM diagnosis code for diffuse follicle center lymphoma, intrathoracic lymph nodes. A type of cancer of the lymph system (diffuse follicle center lymphoma) located in the lymph nodes within the chest cavity. C82.52 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, C82.52 maps to Lymphoma and Other Cancers (HCC 21) with a source-labeled community, non-dual, aged reference coefficient of 0.671. No V24 mapping is shown for C82.52; use the applicable model and payment year when reviewing the V28 mapping. 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. 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.

Intrathoracic involvement should be confirmed by chest imaging; document whether mediastinal or hilar nodes are affected. Because C82.52 maps to an HCC category, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) before the diagnosis is used for risk adjustment. 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, source-labeled coefficient references, and MEAT documentation criteria for C82.52 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Intrathoracic involvement should be confirmed by chest imaging; document whether mediastinal or hilar nodes are affected
•Chest involvement may cause respiratory symptoms; note any associated complications in documentation

Clinical Significance

Diffuse follicle center lymphoma involving intrathoracic lymph nodes may present with mediastinal or hilar lymphadenopathy that can cause compressive symptoms including superior vena cava syndrome, airway compromise, or pleural effusions. Intrathoracic disease often requires cross-sectional imaging for accurate staging and may influence the choice between systemic therapy and radiation. This presentation requires differentiation from other causes of mediastinal lymphadenopathy including sarcoidosis and other lymphoma subtypes.

Documentation Requirements

✓Pathology confirming diffuse follicle center lymphoma
✓Chest CT or PET/CT documenting intrathoracic lymph node involvement with measurements
✓Specification of which intrathoracic nodes are involved (mediastinal, hilar, paratracheal, etc.)
✓Assessment for compressive complications (airway, vascular, esophageal)
✓Staging documentation including assessment of other potential sites

Commonly Confused Codes

•C82.62: Cutaneous follicle center lymphoma, intrathoracic lymph nodes: Cutaneous variant originates in skin; verify the primary lymphoma type
•C82.82: Other types of follicular lymphoma, intrathoracic lymph nodes: Use C82.52 when diffuse follicle center type is confirmed
•C85.22: Mediastinal (thymic) large B-cell lymphoma, intrathoracic: This is a distinct entity from diffuse follicle center lymphoma