C02.4
BillableMalignant neoplasm of lingual tonsil
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C02.4 an HCC code?
Yes. C02.4 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors under the CMS-HCC V28 risk adjustment model (and Colorectal, Bladder, 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 C02.4
For C02.4 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 C02.4 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C02.4 is the ICD-10-CM diagnosis code for malignant neoplasm of lingual tonsil. Cancer of the lingual tonsil, which is lymphoid tissue located at the base of the tongue. C02.4 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of lip, oral cavity and pharynx (c00-c14).
Under the CMS-HCC V28 risk adjustment model, C02.4 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, C02.4 maps to Colorectal, Bladder, and Other Cancers (HCC 11) with a community, non-dual, aged base RAF weight of 0.306. 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.
Lingual tonsil is distinct from palatine tonsils; verify the specific lymphoid tissue involved. Because C02.4 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 C02.4 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Lingual tonsil is distinct from palatine tonsils; verify the specific lymphoid tissue involved
- •Confirm histology as these may be lymphomas rather than squamous cell carcinomas
Clinical Significance
Malignant neoplasm of the lingual tonsil is a cancer of the lymphoid tissue at the base of the tongue. These tumors may be squamous cell carcinoma or lymphoma, and the distinction is critical for treatment planning. HPV-associated squamous cell carcinomas of the lingual tonsil have dramatically better prognosis than HPV-negative tumors, making HPV/p16 testing essential.
Documentation Requirements
- ✓Pathology confirming malignancy with histologic type (squamous cell carcinoma vs lymphoma)
- ✓HPV/p16 immunohistochemistry status documented
- ✓Documentation specifying lingual tonsil as distinct from palatine tonsil
- ✓TNM staging (staged as oropharyngeal cancer)
- ✓Neck lymph node status documented
- ✓Active vs historical cancer status
Excludes 2 — Not included here, may code separately
- malignant neoplasm of tonsil NOS (C09.9)