C40.00
BillableMalignant neoplasm of scapula and long bones of unspecified upper limb
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C40.00 an HCC code?
Yes. C40.00 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 C40.00
For C40.00to 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 C40.00 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C40.00 is the ICD-10-CM diagnosis code for malignant neoplasm of scapula and long bones of unspecified upper limb. Cancer of the bone in an upper arm or forearm (long bones) or shoulder blade (scapula) on an unspecified side. C40.00 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, C40.00 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, C40.00 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.
Determine laterality (right vs. left) from documentation; use C40.01 for right and C40.02 for left if known. Because C40.00 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 C40.00 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
Clinical Significance
Bone cancer of the scapula and long bones of the upper limb without laterality specified represents primary osseous malignancy, most commonly osteosarcoma, Ewing sarcoma, or chondrosarcoma. These sarcomas require multidisciplinary management including orthopedic oncology, chemotherapy, and often limb-salvage surgery. Accurate coding is essential for reflecting the complexity and resource intensity of treatment.
Documentation Requirements
- ✓Pathology confirming primary bone malignancy with histological type (osteosarcoma, Ewing, chondrosarcoma)
- ✓Imaging (X-ray, MRI, bone scan) confirming tumor location in scapula or long bones
- ✓Provider query for laterality
- ✓Specific bone involved (humerus, radius, ulna, scapula)
- ✓TNM staging and treatment plan including limb-salvage vs. amputation assessment
Commonly Confused Codes
- •C40.01/C40.02 — Right/left upper limb long bones: Always assign laterality when documented
- •C79.51 — Secondary malignant neoplasm of bone: Metastatic bone disease is far more common than primary bone cancer
- •C49.1x — Connective tissue of upper limb: Soft tissue sarcomas adjacent to bone use different codes
- •D16.0x — Benign neoplasm of scapula and long bones: Ensure malignancy is confirmed; osteochondromas are benign