D43.0
BillableNeoplasm of uncertain behavior of brain, supratentorial
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D43.0 an HCC code?
Yes. D43.0 maps to Melanoma and Other Skin Cancers under the CMS-HCC V28 risk adjustment model (and Breast, Prostate, and Other Cancers and Tumors 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 D43.0
For D43.0 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 D43.0 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D43.0 is the ICD-10-CM diagnosis code for neoplasm of uncertain behavior of brain, supratentorial. A growth in the upper part of the brain (above the tentorium, a membrane dividing brain regions) that cannot yet be classified as definitely cancer or definitely benign. D43.0 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes (d37-d48).
Under the CMS-HCC V28 risk adjustment model, D43.0 maps to Melanoma and Other Skin Cancers (HCC 23) with a community, non-dual, aged base RAF weight of 0.251. Under the older CMS-HCC V24 model, D43.0 maps to Breast, Prostate, and Other Cancers and Tumors (HCC 12) with a community, non-dual, aged base RAF weight of 0.150. 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.
Supratentorial refers to structures above the tentorium cerebelli; ensure this anatomical distinction is documented. Because D43.0 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 D43.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Supratentorial refers to structures above the tentorium cerebelli; ensure this anatomical distinction is documented
- •This code is for uncertain behavior lesions; confirmed malignant brain tumors use different C-codes
Clinical Significance
Neoplasms of uncertain behavior in the supratentorial brain involve structures above the tentorium cerebelli, including the cerebral hemispheres, basal ganglia, and thalamus. These tumors often represent low-grade gliomas or atypical tumors that have features preventing clear benign or malignant classification, requiring serial imaging and potential biopsy for definitive diagnosis.
Documentation Requirements
- ✓Documentation must specify the supratentorial location, supported by neuroimaging (magnetic resonance imaging) showing the tumor above the tentorium cerebelli.
- ✓Pathology should describe the histological features leading to uncertain behavior classification.
- ✓Document any neurological deficits, seizure history, or mass effect symptoms.
Excludes 1 — Do NOT code together
- neoplasm of uncertain behavior of fourth ventricle (D43.1)