C15.4
BillableMalignant neoplasm of middle third of esophagus
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C15.4 an HCC code?
Yes. C15.4 maps to Lung and Other Severe Cancers under the CMS-HCC V28 risk adjustment model (and Lung and Other Severe 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 C15.4
For C15.4 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 C15.4 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C15.4 is the ICD-10-CM diagnosis code for malignant neoplasm of middle third of esophagus. Cancer of the middle section of the esophagus, the tube that carries food from the throat to the stomach. C15.4 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of digestive organs (c15-c26).
Under the CMS-HCC V28 risk adjustment model, C15.4 maps to Lung and Other Severe Cancers (HCC 20) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, C15.4 mapped to the same category but with a base RAF weight of 0.973 — V28 recalibrated weights across the entire model. 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 middle third of esophagus is approximately from 24-32 cm from the incisor teeth. Because C15.4 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 C15.4 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •The middle third of esophagus is approximately from 24-32 cm from the incisor teeth
- •Ensure documentation specifies middle third location; if unspecified, use C15.9 instead
Clinical Significance
Malignant neoplasm of the middle third of the esophagus represents cancer in the thoracic esophagus at the level of the tracheal bifurcation and aortic arch. This location is surgically challenging due to proximity to vital mediastinal structures, and five-year survival rates remain poor at approximately 15-25% for all stages combined.
Documentation Requirements
- ✓Pathology-confirmed malignancy with histological type
- ✓Documentation specifying middle third of esophagus (approximately 24-32 cm from incisors)
- ✓Endoscopic ultrasound for T and N staging
- ✓PET/CT for metastatic evaluation
- ✓Assessment of mediastinal invasion (trachea, aorta, vertebral body)
- ✓Nutritional status, weight loss documentation, and performance status
Commonly Confused Codes
- •C15.3 — Upper third of esophagus; the upper third is the cervical esophagus, above the middle thoracic portion
- •C15.5 — Lower third of esophagus; the lower third approaches the gastroesophageal junction
- •C15.9 — Esophagus, unspecified; avoid when endoscopy specifies the middle third
- •C34.x — Lung cancer; mediastinal esophageal tumors may be confused with lung masses on imaging