Question 1

What is ICD-10 code Q71.50?

Accepted Answer

Q71.50 is the ICD-10-CM diagnosis code for longitudinal reduction defect of unspecified ulna. A birth defect involving underdevelopment or shortening of the ulna bone (forearm bone on the pinky side) when the specific side is not documented. Q71.50 sits in the ICD-10-CM chapter for congenital malformations, deformations and chromosomal abnormalities (q00-qa0), within the section covering congenital malformations and deformations of the musculoskeletal system (q65-q79).

Q71.50 is a billable ICD-10-CM code, but the current payload does not show a mapping under the CMS-HCC V28, V24, ESRD, or RxHCC models. Do not assign risk adjustment value from this page when no source-backed mapping is shown; verify the applicable model and payment year.

If laterality is documented, use Q71.51 (right) or Q71.52 (left) instead of unspecified.

Question 2

Is Q71.50 an HCC code?

Accepted Answer

No. Q71.50 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 Q71.50 billable?

Accepted Answer

Yes. Q71.50 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. Q71.50 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 Q71.50 map to under V28?

Accepted Answer

Q71.50 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 RAF reference is published for Q71.50?

Accepted Answer

Q71.50 has no separately stated V28 community reference coefficient. Check the current CMS mapping and factor files before using it in any member-score workflow.

Question 6

What is the V28 vs V24 difference for Q71.50?

Accepted Answer

Q71.50 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 Q71.50 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 Q71.50?

Accepted Answer

If laterality is documented, use Q71.51 (right) or Q71.52 (left) instead of unspecified Distinguish from radius defects; confirm ulna is the affected bone from clinical documentation Q71.50 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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Q71.50

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Q71.50 ICD-10-CM Code: Longitudinal reduction defect of unspecified ulna

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Q71.50

Is Q71.50 an HCC code?

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What This Code Means

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