C82.50
BillableDiffuse follicle center lymphoma, unspecified site
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C82.50 an HCC code?
Yes. C82.50 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 C82.50
For C82.50 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 C82.50 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C82.50 is the ICD-10-CM diagnosis code for diffuse follicle center lymphoma, unspecified site. A type of cancer of the lymph system (diffuse follicle center lymphoma) at an unspecified location in the body. C82.50 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, C82.50 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, C82.50 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.
Code C82.50 should only be used when the specific anatomical site is not documented; attempt to obtain site information. Because C82.50 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 C82.50 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Code C82.50 should only be used when the specific anatomical site is not documented; attempt to obtain site information
- •Diffuse follicle center lymphoma is a variant of follicular lymphoma with different prognosis
Clinical Significance
Diffuse follicle center lymphoma at an unspecified site is a distinct variant of follicular lymphoma characterized by a diffuse (non-follicular) growth pattern of follicle center cells. This subtype behaves differently from typical follicular lymphoma and may have a more aggressive course. The unspecified site designation indicates incomplete documentation of anatomical location, which should prompt a query to obtain more specific information for both clinical and coding accuracy.
Documentation Requirements
- ✓Pathology report confirming diffuse follicle center lymphoma (not nodular/follicular pattern)
- ✓Attempt to identify specific anatomical site from imaging or clinical notes
- ✓Staging information (Ann Arbor or Lugano)
- ✓Treatment plan documenting whether active treatment or watchful waiting is appropriate
- ✓Immunohistochemistry results (CD10, BCL6, BCL2) supporting the diagnosis
Commonly Confused Codes
- •C82.40 — Follicular lymphoma grade IIIb, unspecified site: Follicular lymphoma has a follicular growth pattern; diffuse follicle center lymphoma has a diffuse pattern — pathology must specify the architecture
- •C83.30 — Diffuse large B-cell lymphoma, unspecified site: Diffuse large B-cell lymphoma involves large transformed cells; diffuse follicle center lymphoma retains follicle center cell morphology
- •C82.90 — Follicular lymphoma, unspecified, unspecified site: Use C82.50 when the diffuse follicle center type is specified; use C82.90 when the follicular lymphoma type cannot be determined