C43.60
BillableMalignant melanoma of unspecified upper limb, including shoulder
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C43.60 an HCC code?
Yes. C43.60 maps to Prostate, Breast, and Other Cancers and Tumors 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 C43.60
For C43.60to 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 C43.60 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C43.60 is the ICD-10-CM diagnosis code for malignant melanoma of unspecified upper limb, including shoulder. A type of skin cancer (melanoma) that develops on the upper arm, forearm, hand, or shoulder area, but the specific side (right or left) is not documented. This serious cancer requires prompt treatment. C43.60 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering melanoma and other malignant neoplasms of skin (c43-c44).
Under the CMS-HCC V28 risk adjustment model, C43.60 maps to Prostate, Breast, and Other Cancers and Tumors (HCC 23) with a community, non-dual, aged base RAF weight of 0.186. Under the older CMS-HCC V24 model, C43.60 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 cannot be determined from documentation. Because C43.60 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 C43.60 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
Clinical Significance
Malignant melanoma of an unspecified upper limb, including the shoulder, with unspecified laterality. Upper extremity melanoma is common, particularly on the forearms and dorsal hands due to sun exposure. The unspecified laterality should prompt a provider query, as it represents a documentation gap.
Documentation Requirements
- ✓Attempt to clarify laterality (right vs. left) and specific upper limb site
- ✓Breslow depth and ulceration status
- ✓Sentinel lymph node biopsy results (axillary or epitrochlear nodes)
- ✓AJCC staging and mitotic rate
- ✓Treatment plan
- ✓Reason laterality cannot be determined