Question 1

What is ICD-10 code C44.590?

Accepted Answer

C44.590 is the ICD-10-CM diagnosis code for other specified malignant neoplasm of anal skin. A malignant skin tumor of the anal area that is not classified as basal cell or squamous cell carcinoma, representing other specified types of skin cancer in this location. C44.590 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering melanoma and other malignant neoplasms of skin (c43-c44).

C44.590 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 tumor is located on the anal skin, not in the anal canal itself.

Question 2

Is C44.590 an HCC code?

Accepted Answer

No. C44.590 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 C44.590 billable?

Accepted Answer

Yes. C44.590 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. C44.590 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

Which HCC does C44.590 map to under V28?

Accepted Answer

C44.590 does not map to a CMS-HCC V28 payment category. Check the current CMS-HCC V28 model file for payment year 2026 rather than an older V24 tip sheet.

Question 5

What does C44.590 pay in RAF?

Accepted Answer

C44.590 has no separately stated V28 community RAF weight. If it is not a V28 payment HCC, it adds nothing to a community RAF score.

Question 6

What is the V28 vs V24 difference for C44.590?

Accepted Answer

C44.590 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 community model rewards C44.590 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's V28/V24 community RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a community payment HCC.

Question 7

What documentation supports C44.590?

Accepted Answer

Confirm the tumor is located on the anal skin, not in the anal canal itself Verify the histological type does not fit basal cell (C44.51) or squamous cell (C44.52) categories C44.590 is not a CMS-HCC payment code, so MEAT is not the payment hook. Documentation still has to support the diagnosis if you report it.

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C44.590

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C44.590 ICD-10-CM Code: Other specified malignant neoplasm of anal skin

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C44.590

Is C44.590 an HCC code?

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