C83.01
BillableSmall cell B-cell lymphoma, lymph nodes of head, face, and neck
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C83.01 an HCC code?
Yes. C83.01 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors under the CMS-HCC V28 risk adjustment model (and Lymphoma and Other Cancers under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.
MEAT Criteria for C83.01
For C83.01 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 C83.01 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C83.01 is the ICD-10-CM diagnosis code for small cell b-cell lymphoma, lymph nodes of head, face, and neck. A type of cancer of the lymph system (small cell B-cell lymphoma) affecting the lymph nodes in the head, face, and neck region. C83.01 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, C83.01 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors (HCC 21) with a community, non-dual, aged base RAF weight of 0.545. Under the older CMS-HCC V24 model, C83.01 maps to Lymphoma and Other Cancers (HCC 10) with a community, non-dual, aged base RAF weight of 0.675. 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.
Confirm documentation specifies head, face, or neck lymph node involvement; this includes cervical, submandibular, and facial nodes. Because C83.01 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 C83.01 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm documentation specifies head, face, or neck lymph node involvement; this includes cervical, submandibular, and facial nodes
- •Document laterality (right, left, or bilateral) in the medical record for clinical reference
Clinical Significance
Small cell B-cell lymphoma involving head, face, and neck lymph nodes is a common initial presentation, as cervical lymphadenopathy is one of the most frequent presenting signs. This low-grade lymphoma is the tissue counterpart of chronic lymphocytic leukemia and has an indolent course. Head and neck presentation may be discovered incidentally or during evaluation for painless lymphadenopathy. Accurate differentiation from other causes of cervical lymphadenopathy requires pathologic confirmation.
Documentation Requirements
- ✓Pathology confirming small cell B-cell lymphoma histology
- ✓Immunophenotyping results (CD5+, CD23+, CD20 dim) supporting the diagnosis
- ✓Documentation of specific head, face, or neck lymph nodes involved
- ✓Peripheral blood assessment for circulating disease (to distinguish from chronic lymphocytic leukemia)
- ✓Staging evaluation including imaging
- ✓Flow cytometry results
Commonly Confused Codes
- •C91.11 — Chronic lymphocytic leukemia of B-cell type, in remission: Small cell B-cell lymphoma is the nodal form; chronic lymphocytic leukemia is the leukemic form of the same disease
- •C82.91 — Follicular lymphoma, unspecified, lymph nodes of head, face, and neck: Different lymphoma subtype with distinct immunophenotype
- •C83.31 — Diffuse large B-cell lymphoma, lymph nodes of head, face, and neck: Large cell type rather than small cell; different disease behavior