H49.21
BillableSixth [abducent] nerve palsy, right eye
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is H49.21 an HCC code?
No. H49.21 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
H49.21 is the ICD-10-CM diagnosis code for sixth [abducent] nerve palsy, right eye. Paralysis of the sixth cranial nerve (abducent nerve) affecting the right eye, causing inability to move the right eye outward and resulting in inward eye deviation. H49.21 sits in the ICD-10-CM chapter for diseases of the eye and adnexa (h00-h59), within the section covering disorders of ocular muscles, binocular movement, accommodation and refraction (h49-h52).
H49.21 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.
The abducent nerve is the most commonly affected cranial nerve; document any underlying causes such as diabetes or increased intracranial pressure.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for H49.21 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •The abducent nerve is the most commonly affected cranial nerve; document any underlying causes such as diabetes or increased intracranial pressure
- •Confirm right eye laterality is documented