Question 1

What is ICD-10 code C44.799?

Accepted Answer

C44.799 is the ICD-10-CM diagnosis code for other specified malignant neoplasm of skin of left lower limb, including hip. A rare or unusual type of skin cancer on the left lower leg or hip area that is not classified as basal cell or squamous cell carcinoma. C44.799 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering melanoma and other malignant neoplasms of skin (c43-c44).

C44.799 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

Verify left side laterality is clearly documented in the medical record.

Question 2

Is C44.799 an HCC code?

Accepted Answer

No. C44.799 is a billable ICD-10-CM code but does not map to any payment HCC category under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can still be reported on Medicare Advantage encounter data submissions, but it does not contribute to the beneficiary's Risk Adjustment Factor (RAF) score and therefore does not affect the risk-adjusted capitation payment to the plan. V28 reached 100% phase-in for payment year 2026.

Question 3

Is C44.799 billable?

Accepted Answer

Yes. C44.799 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. C44.799 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Question 4

What is the V28 vs V24 difference for C44.799?

Accepted Answer

C44.799 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards C44.799 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

Question 5

What should coders know when reporting C44.799?

Accepted Answer

Verify left side laterality is clearly documented in the medical record Confirm the specific malignancy type is documented and does not fit basal cell or squamous cell classifications

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C44.799

Is C44.799 an HCC code?

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C44.799 ICD-10-CM Code: Other specified malignant neoplasm of skin of left lower limb, including hip

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C44.799

Is C44.799 an HCC code?

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