C83.35
BillableDiffuse large B-cell lymphoma, lymph nodes of inguinal region and lower limb
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C83.35 an HCC code?
Yes. C83.35 maps to Lung and Other Severe Cancers 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 C83.35
For C83.35to 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 C83.35 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C83.35 is the ICD-10-CM diagnosis code for diffuse large b-cell lymphoma, lymph nodes of inguinal region and lower limb. A type of aggressive blood cancer (diffuse large B-cell lymphoma) affecting lymph nodes in the groin and lower legs. C83.35 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, C83.35 maps to Lung and Other Severe Cancers (HCC 20) with a community, non-dual, aged base RAF weight of 1.136. Under the older CMS-HCC V24 model, C83.35 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.
Inguinal lymph nodes are the primary focus; confirm documentation specifies groin/lower limb involvement. Because C83.35 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 C83.35 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Inguinal lymph nodes are the primary focus; confirm documentation specifies groin/lower limb involvement
- •Note laterality (right vs. left) if documented, as this may impact staging and treatment decisions
Clinical Significance
Diffuse large B-cell lymphoma of inguinal and lower limb lymph nodes requires differentiation from other causes of groin lymphadenopathy including infections, reactive conditions, and metastatic disease from skin or genital malignancies. DLBCL in this location typically presents as rapidly growing, painless nodal masses.
Documentation Requirements
- ✓Pathology confirmation of DLBCL from inguinal node biopsy
- ✓Documentation specifying inguinal and/or lower limb lymph node involvement
- ✓Laterality (right, left, bilateral)
- ✓Imaging documenting extent of inguinal/lower limb lymphadenopathy
- ✓Exclusion of other causes of inguinal lymphadenopathy
Commonly Confused Codes
- •C83.36 — DLBCL, intrapelvic; inguinal nodes are superficial/external while intrapelvic are deep within pelvis
- •C83.15 — Mantle cell lymphoma, inguinal/lower limb; different subtype
- •C77.4 — Secondary malignant neoplasm of inguinal lymph nodes; for metastatic disease, not primary lymphoma
- •C83.35 vs C83.38 — If multiple regions beyond inguinal are involved, use multiple sites code