C02.1
BillableMalignant neoplasm of border of tongue
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C02.1 an HCC code?
Yes. C02.1 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 C02.1
For C02.1 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 C02.1 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C02.1 is the ICD-10-CM diagnosis code for malignant neoplasm of border of tongue. Cancer that develops along the edges or sides of the tongue. C02.1 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, C02.1 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, C02.1 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.
Border of tongue includes the lateral margins; verify documentation specifies edge location. Because C02.1 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 C02.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Border of tongue includes the lateral margins; verify documentation specifies edge location
- •Do not confuse with anterior two-thirds unspecified (C02.3) which may include border areas
Clinical Significance
Malignant neoplasm of the border (lateral margin) of the tongue is the most common location for oral tongue cancer, accounting for approximately 45% of all tongue malignancies. The lateral border has the highest concentration of carcinogen exposure from tobacco and alcohol. Early detection is critical as lateral tongue cancers are accessible for clinical examination but can rapidly invade deep musculature.
Documentation Requirements
- ✓Pathology confirming malignancy with histologic type (usually squamous cell carcinoma)
- ✓Documentation specifying border/lateral margin as the primary site
- ✓Laterality documented: right, left, or bilateral involvement
- ✓Depth of invasion measured in millimeters (critical for T-staging in 8th edition AJCC)
- ✓Neck lymph node status: clinical and/or pathologic
- ✓Active treatment plan vs surveillance