Question 1

What is ICD-10 code Q17.8?

Accepted Answer

Q17.8 is the ICD-10-CM diagnosis code for other specified congenital malformations of ear. A birth defect of the ear structure that doesn't fit into the other specified categories of ear malformations. Q17.8 sits in the ICD-10-CM chapter for congenital malformations, deformations, chromosomal abnormalities, and genetic disorders (q00-qa0), within the section covering congenital malformations of eye, ear, face and neck (q10-q18).

Q17.8 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.

This is a catch-all code; use only when the specific type of ear malformation is not better described by Q17.0-Q17.5.

Question 2

Is Q17.8 an HCC code?

Accepted Answer

No. Q17.8 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 Q17.8 billable?

Accepted Answer

Yes. Q17.8 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. Q17.8 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 Q17.8?

Accepted Answer

Q17.8 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 Q17.8 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 Q17.8?

Accepted Answer

This is a catch-all code; use only when the specific type of ear malformation is not better described by Q17.0-Q17.5 Document the specific malformation details to support medical necessity and justify the code selection

Q17.8

Is Q17.8 an HCC code?

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Open Q17.8 in the Interactive Encoder