What is ICD-10 code C83.31?

C83.31 is the ICD-10-CM diagnosis code for Diffuse large B-cell lymphoma, lymph nodes of head, face, and neck. A type of aggressive blood cancer (diffuse large B-cell lymphoma) affecting lymph nodes in the head, face, and neck area. It belongs to the ICD-10-CM chapter for neoplasms (c00-d49). C83.31 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. C83.31 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. C83.31 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. C83.31 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 C83.31 map to under V28?

C83.31 maps to CMS-HCC V28 HCC 20 (Lung and Other Severe Cancers). The category numbers, labels, and conditions come from the CMS-HCC V28 model file for payment year 2026.

2026 ICD-10-CM C83.31: Diffuse large B-cell

C83.31 maps to CMS-HCC V28 20. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · free HCC coding tools

ICD-10-CM Code View

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Code lookupC83.31

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

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

C83.31

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

Diffuse large B-cell lymphoma, lymph nodes of head, face, and neck

A type of aggressive blood cancer (diffuse large B-cell lymphoma) affecting lymph nodes in the head, face, and neck area.

Buddy Insight

Diffuse large B-cell lymphoma of head, face, and neck lymph nodes is a common presentation, as cervical lymphadenopathy is one of the most frequent initial findings.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 20

Lung and Other Severe 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

C83Non-follicular lymphoma C83.3Diffuse large B-cell lymphoma C83.31Diffuse large B-cell lymphoma, lymph nodes of head, face, and neck

Inclusion Terms

Official

Anaplastic diffuse large B-cell lymphomaInherited from C83.3
CD30-positive diffuse large B-cell lymphomaInherited from C83.3
Centroblastic diffuse large B-cell lymphomaInherited from C83.3
Diffuse large B-cell lymphoma, subtype not specifiedInherited from C83.3
Immunoblastic diffuse large B-cell lymphomaInherited from C83.3
Plasmablastic diffuse large B-cell lymphomaInherited from C83.3
T-cell rich diffuse large B-cell lymphomaInherited from C83.3

Excludes 2

Official

Kaposi's sarcoma of lymph nodes (C46.3)Inherited from C81-C96
secondary and unspecified neoplasm of lymph nodes (C77.-)Inherited from C81-C96
secondary neoplasm of bone marrow (C79.52)Inherited from C81-C96
secondary neoplasm of spleen (C78.89)Inherited from C81-C96

Related Codes

Official

C83.30Diffuse large B-cell lymphoma, unspecified site C83.32Diffuse large B-cell lymphoma, intrathoracic lymph nodes C83.33Diffuse large B-cell lymphoma, intra-abdominal lymph nodes C83.34Diffuse large B-cell lymphoma, lymph nodes of axilla and upper limb C83.35Diffuse large B-cell lymphoma, lymph nodes of inguinal region and lower limb

Includes

Official

No Includes notes are included in this display for C83.31. Check the code and parent instructions in the Code Book.

Excludes 1

Official

personal history of non-Hodgkin lymphoma (Z85.72)Inherited from C83, C83.3
mediastinal (thymic) large B-cell lymphoma (C85.2-)Inherited from C83, C83.3
mature T/NK-cell lymphomas (C84.-)Inherited from C83, C83.3

Code First

Official

No Code First sequencing instructions are included in this display for C83.31. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for C83.31. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for C83.31. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Pathology confirmation of DLBCL with immunohistochemistry panel

Documentation specifying head, face, or neck lymph node involvement

Imaging (CT neck, PET/CT) documenting lymphadenopathy location and extent

Assessment for Waldeyer ring or other extranodal head/neck involvement

MEAT Support

HCC Buddy guidance

Pathology confirmation of DLBCL with immunohistochemistry panel

Documentation specifying head, face, or neck lymph node involvement

Imaging (CT neck, PET/CT) documenting lymphadenopathy location and extent

Assessment for Waldeyer ring or other extranodal head/neck involvement

Audit Caution

HCC Buddy guidance

Coding Waldeyer ring involvement as nodal disease when it is actually extranodal (C83.398)

Using multiple site code for involvement of different node levels within the neck (all neck nodes are one site)

Not distinguishing between DLBCL and Hodgkin lymphoma which can present similarly in cervical nodes

Common Mistakes

HCC Buddy guidance

C83.11 — Mantle cell lymphoma, head/face/neck; different subtype requiring pathology distinction

C83.398 — DLBCL, extranodal/solid organ; use for tonsillar or sinonasal involvement, not nodal disease

C81.11 — Nodular sclerosis Hodgkin lymphoma, head/face/neck; Reed-Sternberg cells distinguish Hodgkin from DLBCL

C83.38 — DLBCL, multiple sites; use C83.31 when involvement is limited to head/face/neck region

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 C83.31 an HCC code?

Yes. C83.31 (Diffuse large B-cell lymphoma, lymph nodes of head, face, and neck) maps to HCC 20, Lung and Other Severe Cancers under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 1.136. 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: C83.31 is billable and maps to V28 HCC 20, Lung and Other Severe Cancers. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: C83.31
Description: Diffuse large B-cell lymphoma, lymph nodes of head, face, and neck
HCC (V28): HCC 20 — Lung and Other Severe Cancers
RAF reference coefficient: 1.136
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 20, Lung and Other Severe Cancers

1.136

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 C83.31 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for C83.31

For C83.31, 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.

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

Coder workflow notes

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What This Code Means

C83.31 is the ICD-10-CM diagnosis code for diffuse large b-cell lymphoma, lymph nodes of head, face, and neck. A type of aggressive blood cancer (diffuse large B-cell lymphoma) affecting lymph nodes in the head, face, and neck area. C83.31 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, C83.31 maps to Lung and Other Severe Cancers (HCC 20) with a source-labeled community, non-dual, aged reference coefficient of 1.136. No V24 mapping is shown for C83.31; use the applicable model and payment year when reviewing the V28 mapping. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. 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.

Verify the specific anatomical site documented in the pathology report to ensure accurate site selection. For C83.31, 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. 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 C83.31 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify the specific anatomical site documented in the pathology report to ensure accurate site selection
•Confirm this is diffuse large B-cell lymphoma (DLBCL) and not another lymphoma subtype before coding

Clinical Significance

Diffuse large B-cell lymphoma of head, face, and neck lymph nodes is a common presentation, as cervical lymphadenopathy is one of the most frequent initial findings. Head and neck DLBCL may also involve Waldeyer ring, nasal sinuses, or salivary glands, requiring careful distinction between nodal and extranodal disease.

Documentation Requirements

✓Pathology confirmation of DLBCL with immunohistochemistry panel
✓Documentation specifying head, face, or neck lymph node involvement
✓Imaging (CT neck, PET/CT) documenting lymphadenopathy location and extent
✓Assessment for Waldeyer ring or other extranodal head/neck involvement
✓ENT evaluation if oropharyngeal involvement is suspected

Commonly Confused Codes

•C83.11: Mantle cell lymphoma, head/face/neck; different subtype requiring pathology distinction
•C83.398: DLBCL, extranodal/solid organ; use for tonsillar or sinonasal involvement, not nodal disease
•C81.11: Nodular sclerosis Hodgkin lymphoma, head/face/neck; Reed-Sternberg cells distinguish Hodgkin from DLBCL
•C83.38: DLBCL, multiple sites; use C83.31 when involvement is limited to head/face/neck region