C41.3
BillableMalignant neoplasm of ribs, sternum and clavicle
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C41.3 an HCC code?
Yes. C41.3 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 C41.3
For C41.3 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 C41.3 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C41.3 is the ICD-10-CM diagnosis code for malignant neoplasm of ribs, sternum and clavicle. This code describes cancer that originates in the bones of the chest wall, including the ribs, breastbone (sternum), or collarbone (clavicle). These are primary bone cancers rather than cancers that have spread to these bones from elsewhere. C41.3 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, C41.3 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, C41.3 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 whether the cancer is primary (originated in the bone) or secondary (metastatic from another site), as metastatic bone cancers use different codes. Because C41.3 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 C41.3 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify whether the cancer is primary (originated in the bone) or secondary (metastatic from another site), as metastatic bone cancers use different codes
- •Document the specific bone location (rib, sternum, or clavicle) in the medical record to support accurate code selection and ensure laterality is noted when applicable
Clinical Significance
Primary malignant neoplasm of the ribs, sternum, and clavicle. These chest wall bone cancers include chondrosarcoma (most common in ribs), osteosarcoma, and Ewing sarcoma. Chest wall resection with reconstruction is often required. Distinction from metastatic disease is critical, as rib metastases from breast and lung cancer are far more common.
Documentation Requirements
- ✓Specific bone involved (which rib(s), sternum, or clavicle)
- ✓Laterality for rib and clavicle involvement
- ✓Histologic type from pathology — chondrosarcoma is most common in ribs
- ✓Primary vs. metastatic origin confirmed — rib metastases from breast cancer are extremely common
- ✓Extent of chest wall involvement and any lung or pleural invasion
- ✓Treatment plan (surgical resection, reconstruction, adjuvant therapy)