C10.1
BillableMalignant neoplasm of anterior surface of epiglottis
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C10.1 an HCC code?
Yes. C10.1 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 C10.1
For C10.1 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 C10.1 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C10.1 is the ICD-10-CM diagnosis code for malignant neoplasm of anterior surface of epiglottis. Cancer of the front-facing surface of the epiglottis, which is the flap of tissue that covers the airway when swallowing. C10.1 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, C10.1 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, C10.1 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.
The anterior surface of the epiglottis is the side facing toward the base of the tongue. Because C10.1 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 C10.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •The anterior surface of the epiglottis is the side facing toward the base of the tongue
- •Distinguish from the posterior surface or laryngeal surface of the epiglottis, which would be coded differently
Clinical Significance
Malignant neoplasm of the anterior surface of the epiglottis is classified as an oropharyngeal cancer because the anterior (lingual) surface faces the tongue base. This distinction is critical because the posterior (laryngeal) surface of the epiglottis is classified as supraglottic laryngeal cancer with different coding and staging implications.
Documentation Requirements
- ✓Pathology-confirmed malignancy specifying anterior (lingual) surface of epiglottis
- ✓Clear documentation distinguishing anterior from posterior epiglottic surface
- ✓HPV/p16 status (relevant as an oropharyngeal cancer)
- ✓TNM staging using oropharyngeal (not laryngeal) staging criteria
- ✓Assessment of extension to vallecula, tongue base, or other structures
Excludes 2 — Not included here, may code separately
- malignant neoplasm of epiglottis (suprahyoid portion) NOS (C32.1)
Commonly Confused Codes
- •C32.1 — Malignant neoplasm of supraglottis; the posterior/laryngeal surface of epiglottis is coded as supraglottic, not C10.1
- •C10.0 — Vallecula; adjacent site below the anterior epiglottis
- •C10.8 — Overlapping sites of oropharynx; use when tumor spans anterior epiglottis and adjacent oropharyngeal sites
- •C01 — Base of tongue; anterior epiglottic tumors may extend to tongue base