C82.00
BillableFollicular lymphoma grade I, unspecified site
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C82.00 an HCC code?
Yes. C82.00 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 C82.00
For C82.00 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 C82.00 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C82.00 is the ICD-10-CM diagnosis code for follicular lymphoma grade i, unspecified site. A slow-growing type of lymphoma called follicular lymphoma grade I that is present but the specific location in the body is not documented. C82.00 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, C82.00 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, C82.00 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.
Grade I indicates the lowest grade (most differentiated) follicular lymphoma. Because C82.00 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 C82.00 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
Clinical Significance
Follicular lymphoma grade I is the most indolent form of follicular lymphoma, a slow-growing non-Hodgkin B-cell lymphoma. Grade I indicates predominantly small cleaved cells (centrocytes) with fewer than 5 centroblasts per high-power field, carrying the best prognosis among follicular lymphoma grades. Despite its indolent nature, follicular lymphoma is generally considered incurable with standard therapy, requiring long-term monitoring and intermittent treatment over many years.
Documentation Requirements
- ✓Pathology report confirming follicular lymphoma with grade I classification (0-5 centroblasts per high-power field)
- ✓Query provider for anatomic site information to assign a more specific code than unspecified
- ✓Staging workup results (Ann Arbor staging)
- ✓Documentation of treatment approach: watch-and-wait versus active therapy
- ✓Flow cytometry or immunohistochemistry results confirming B-cell lineage (CD20+, CD10+, BCL-2+)
Commonly Confused Codes
- •C82.10 — Follicular lymphoma grade II, unspecified site: grade II has 6-15 centroblasts per high-power field; this distinction is made on pathology and affects treatment decisions
- •C82.20 — Follicular lymphoma grade III, unspecified: grade III is more aggressive and may require different treatment; centroblast count exceeds 15 per high-power field
- •C81.40 — Lymphocyte-rich Hodgkin lymphoma, unspecified: Hodgkin lymphoma is a completely different entity; pathology shows Reed-Sternberg cells in Hodgkin but follicular architecture in follicular lymphoma
- •C83.10 — Mantle cell lymphoma, unspecified: another B-cell lymphoma with a different immunophenotype (cyclin D1+) and more aggressive clinical course