C41.0
BillableMalignant neoplasm of bones of skull and face
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C41.0 an HCC code?
Yes. C41.0 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors under the CMS-HCC V28 risk adjustment model (and Lymphoma 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 C41.0
For C41.0 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 C41.0 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C41.0 is the ICD-10-CM diagnosis code for malignant neoplasm of bones of skull and face. This code represents cancer that starts in the bones of the skull or facial bones. It is a serious condition where malignant (cancerous) cells develop in these bone structures. C41.0 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of bone and articular cartilage (c40-c41).
Under the CMS-HCC V28 risk adjustment model, C41.0 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, C41.0 maps to Lymphoma and Other Cancers (HCC 10) with a community, non-dual, aged base RAF weight of 0.675. 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.
Verify the specific bone location (skull vault, facial bones, jaw) in the documentation to ensure accurate coding and consider if more specific codes apply. Because C41.0 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 C41.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify the specific bone location (skull vault, facial bones, jaw) in the documentation to ensure accurate coding and consider if more specific codes apply
- •Distinguish between primary bone cancer (C41.0) and metastatic cancer that has spread to skull/facial bones, which would use different coding
Clinical Significance
Primary malignant neoplasm of the bones of the skull and face, excluding the mandible (coded separately at C41.1). These cancers include chordomas, osteosarcomas, and chondrosarcomas of the cranial vault and facial bones. Due to proximity to the brain and vital structures, these tumors carry significant surgical morbidity and often require multidisciplinary management.
Documentation Requirements
- ✓Specific skull or facial bone involved (frontal, parietal, temporal, sphenoid, ethmoid, zygomatic, maxilla, etc.)
- ✓Histologic type from biopsy or surgical pathology
- ✓Primary vs. metastatic origin — skull metastases from breast and lung cancer are far more common than primary skull tumors
- ✓Tumor staging and grade
- ✓Involvement of or proximity to intracranial structures
- ✓Treatment plan and surgical approach
Excludes 2 — Not included here, may code separately
Commonly Confused Codes
- •C41.1 — Malignant neoplasm of mandible; the lower jaw is coded separately from skull and facial bones
- •C79.51 — Secondary malignant neoplasm of bone; skull metastases from breast, lung, or kidney cancer are far more common
- •C71.x — Malignant neoplasm of brain; primary brain tumors are coded differently from skull bone tumors
- •C31.x — Malignant neoplasm of accessory sinuses; sinus cancers are mucosal, not bone