C82.40
BillableFollicular lymphoma grade IIIb, unspecified site
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C82.40 an HCC code?
Yes. C82.40 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 C82.40
For C82.40 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 C82.40 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C82.40 is the ICD-10-CM diagnosis code for follicular lymphoma grade iiib, unspecified site. A type of cancer of the lymph system (follicular lymphoma) that is grade IIIb with an unspecified or unknown location. C82.40 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, C82.40 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, C82.40 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.
Use this code only when the specific anatomical site cannot be determined from documentation. Because C82.40 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 C82.40 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code only when the specific anatomical site cannot be determined from documentation
- •Grade IIIb is a higher grade than IIIa, indicating more aggressive disease; verify grade documentation
Clinical Significance
Follicular lymphoma grade IIIb at an unspecified site is the most aggressive subtype of follicular lymphoma, characterized by sheets of centroblasts without centrocytes. Grade IIIb is biologically and clinically more similar to diffuse large B-cell lymphoma than to indolent follicular lymphoma and is treated with aggressive chemoimmunotherapy regimens. The unspecified site warrants a provider query.
Documentation Requirements
- ✓Pathology report confirming grade IIIb (sheets of centroblasts, no centrocytes)
- ✓Expert hematopathology review recommended to distinguish from DLBCL
- ✓Query provider for specific anatomic site
- ✓Ann Arbor staging with performance status
- ✓Aggressive treatment plan documentation (R-CHOP or similar)
Commonly Confused Codes
- •C82.30 — Grade IIIa, unspecified site; IIIa has centrocytes present, IIIb does not
- •C82.20 — Grade III unspecified; use C82.40 when pathology specifically confirms IIIb
- •C83.30 — Diffuse large B-cell lymphoma, unspecified site; grade IIIb can be very difficult to differentiate from DLBCL — expert pathology review is recommended
- •C82.10 — Grade II, unspecified site; much lower grade with different management