H49.1 — Fourth [trochlear] nerve palsy
Is H49.1 billable?
No — H49.1 is a non-billable header code. H49.1 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 4 billable codes beneath H49.1.
H49.1 at a glance
| Code | H49.1 |
|---|---|
| Description | Fourth [trochlear] nerve palsy |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
How is H49.1 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to H49.1. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Strabismus › paralytic › fourth nerve (congenital) (nonparalytic)
- Strabismus › paralytic › trochlear nerve (congenital) (nonparalytic)
Excludes2 — not included here — inherited from Chapter 7
The conditions below are not part of H49.1, but a patient may have both at the same time. When documentation supports it, H49.1 and the excluded code may both be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- diabetes mellitus related eye conditions (E09.3-, E10.3-, E11.3-, E13.3-)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury (trauma) of eye and orbit (S05.-)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
- syphilis related eye disorders (A50.01, A50.3-, A51.43, A52.71)
Excludes2 — not included here — inherited from H49-H52
The conditions below are not part of H49.1, but a patient may have both at the same time. When documentation supports it, H49.1 and the excluded code may both be reported.
- nystagmus and other irregular eye movements (H55)
Excludes2 — not included here — inherited from H49
The conditions below are not part of H49.1, but a patient may have both at the same time. When documentation supports it, H49.1 and the excluded code may both be reported.
What codes fall under H49.1? (4)
How long has H49.1 existed?
H49.1 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.