C76.40
BillableMalignant neoplasm of unspecified upper limb
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C76.40 an HCC code?
Yes. C76.40 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 C76.40
For C76.40 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 C76.40 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C76.40 is the ICD-10-CM diagnosis code for malignant neoplasm of unspecified upper limb. Cancer that has developed in an upper arm or hand, but the specific side (left or right) is not documented. C76.40 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of ill-defined, other secondary and unspecified sites (c76-c80).
Under the CMS-HCC V28 risk adjustment model, C76.40 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, C76.40 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.
Use this code only when laterality (left/right) cannot be determined from documentation; otherwise use C76.41 or C76.42. Because C76.40 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 C76.40 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
Clinical Significance
Malignant neoplasm of an unspecified upper limb represents cancer in the upper extremity (arm, forearm, hand) where the specific tissue, site, or laterality cannot be determined. This is an ill-defined site code used when the malignancy overlaps or involves structures that cannot be attributed to a specific tissue of origin.
Documentation Requirements
- ✓Documentation confirming upper limb malignancy
- ✓Laterality — query provider for right (C76.41) or left (C76.42) specification
- ✓Pathology identifying tissue type (bone, soft tissue, skin, nerve)
- ✓Imaging documenting tumor location and extent within the upper extremity
- ✓Attempts to determine specific tissue of origin for more precise coding
Commonly Confused Codes
- •C76.41/C76.42 — Right/left upper limb: Use lateralized codes when side is documented
- •C40.00-C40.02 — Malignant neoplasm of scapula/long bones of upper limb: Bone tumors have specific codes
- •C49.10-C49.12 — Malignant neoplasm of connective tissue of upper limb: Soft tissue sarcomas have specific codes
- •C43.60-C43.62 — Melanoma of upper limb: Skin melanoma has specific codes
- •C44.60-C44.69 — Other skin cancer of upper limb: Non-melanoma skin cancer has specific codes