ICD-10 Code H49.11 – Fourth [trochlear] nerve palsy, right eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H49.11 – Fourth [trochlear] nerve palsy, right eye
What it is
Use this code for paralysis or weakness of the right fourth cranial nerve, which controls the superior oblique muscle. It causes misalignment of the right eye due to impaired downward and inward movement.
Clinical signs
Typical findings include vertical diplopia, worse on down gaze, and a compensatory head tilt away from the affected side. Clinical features vary; refer to documentation.
When to use this code
Assign H49.11 when the provider documents right trochlear nerve palsy, fourth nerve palsy, or right superior oblique palsy affecting the right eye. Use it for confirmed neurologic or ocular motor dysfunction, not for nonspecific eye pain or blurred vision alone.
Do not use for
Do not use this code for left-sided, bilateral, or unspecified fourth nerve palsy. Check documentation if the note describes a different cranial nerve disorder or a transient diplopia without a documented palsy.
Coding tip
Code the laterality exactly as documented; right eye involvement is required for H49.11.