H49.1 – Fourth [trochlear] nerve palsy
ICD-10-CM 2027 diagnosis code · Disorders of ocular muscles, binocular movement, accommodation and refraction
- Code
H49.1(claims format:H491)- Description
- Fourth [trochlear] nerve palsy
- Billable
- No – use a more specific code below
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 7. Diseases of the eye and adnexa (H00-H59)
- Block
- H49-H52 Disorders of ocular muscles, binocular movement, accommodation and refraction
- Parent codes
- H49
Billable codes under H49.1
H49.1 is a header code and cannot be used on claims. Choose the most specific code:
Notes inherited from parent codes
Instructional notes at a category or block level apply to every code below it.
H49 – Paralytic strabismus
Block H49-H52
- nystagmus and other irregular eye movements (H55)
Index terms for H49.1
Entries in the ICD-10-CM alphabetic index that lead to this code:
Related codes in H49
Frequently asked questions
What is ICD-10 code H49.1?
H49.1 is the ICD-10-CM code for fourth [trochlear] nerve palsy, in the block H49-H52 (Disorders of ocular muscles, binocular movement, accommodation and refraction).
Is H49.1 a billable code?
No. H49.1 is a header code with more specific child codes; report one of the billable codes listed above.
What category does H49.1 belong to?
It belongs to category H49 – Paralytic strabismus.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.