Question 1

What is ICD-10 code C44.501?

Accepted Answer

C44.501 is the ICD-10-CM diagnosis code for unspecified malignant neoplasm of skin of breast. A malignant skin cancer of the breast area where the specific type (basal cell, squamous cell, or other) has not been determined or specified. C44.501 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering melanoma and other malignant neoplasms of skin (c43-c44).

C44.501 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.

Confirm the malignancy is of the skin of the breast, not breast tissue itself.

Question 2

Is C44.501 an HCC code?

Accepted Answer

No. C44.501 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 C44.501 billable?

Accepted Answer

Yes. C44.501 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. C44.501 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 C44.501?

Accepted Answer

C44.501 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 C44.501 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 C44.501?

Accepted Answer

Confirm the malignancy is of the skin of the breast, not breast tissue itself Update to a more specific code once histological type is determined

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C44.501

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C44.501 ICD-10-CM Code: Unspecified malignant neoplasm of skin of breast

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C44.501

Is C44.501 an HCC code?

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