H49.1Header code — not billable
Fourth [trochlear] nerve palsy
- Chapter
- 7. Diseases of the eye and adnexa
- Category
- H49
- Effective date
- October 1, 2026
Related codes in category H49
H49Paralytic strabismusH49.0Third [oculomotor] nerve palsyH49.00Third [oculomotor] nerve palsy, unspecified eyeYesH49.01Third [oculomotor] nerve palsy, right eyeYesH49.02Third [oculomotor] nerve palsy, left eyeYesH49.03Third [oculomotor] nerve palsy, bilateralYesH49.10Fourth [trochlear] nerve palsy, unspecified eyeYesH49.11Fourth [trochlear] nerve palsy, right eyeYesH49.12Fourth [trochlear] nerve palsy, left eyeYesH49.13Fourth [trochlear] nerve palsy, bilateralYesH49.2Sixth [abducent] nerve palsyH49.20Sixth [abducent] nerve palsy, unspecified eyeYes
Frequently asked questions
What is ICD-10 code H49.1?
H49.1 is an ICD-10-CM diagnosis code for Fourth [trochlear] nerve palsy.
Is H49.1 a billable code?
No. H49.1 is a category/header code, not billable on its own — use one of its more specific child codes instead.
What ICD-10-CM chapter is H49.1 in?
H49.1 falls under Chapter 7: Diseases of the eye and adnexa.
When did H49.1 become effective?
H49.1 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to H49.1?
H49.1 belongs to category H49, which includes 12 other codes — see the related codes list on this page.
ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.