2027 ICD-10-CM Diagnosis Code H55.01Congenital nystagmus
ICD-10-CM Codes›H00–H59›H55-H57›H55
- Billable — Valid for Submission
- Not Chronic
H55.01 is a billable ICD-10-CM diagnosis code for congenital nystagmus. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 124 through 125. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified eye disorders.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- 2q partial trisomy syndrome
- Acquired esotropia
- Autosomal recessive cerebellar ataxia, pyramidal signs, nystagmus, oculomotor apraxia syndrome
- Congenital nystagmus
- Congenital nystagmus with sensory abnormality
- Congenital nystagmus without sensory abnormality
- Congenital periodic alternating nystagmus
- Epiphyseal dysplasia, microcephalus, nystagmus syndrome
- Esotropia with nystagmus
- Esotropia with nystagmus block
- Infantile esotropia
- Partial trisomy of chromosome 2
- Pendular nystagmus
- Periodic alternating nystagmus
- Progressive microcephaly
- Spastic paraplegia, intellectual disability, nystagmus, obesity syndrome
- Syndactyly, nystagmus syndrome due to 2q31.1 microduplication
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to H55.01: its own notes plus those printed at Chapter 7. A note printed at a category, block or chapter applies to every code under it.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may 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)
Notes
General instructions on how these codes are used.
- Use an external cause code following the code for the eye condition, if applicable, to identify the cause of the eye condition
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name H55.01, its category, or a range that includes it.
Excludes1 1
These codes carry an Excludes1 note naming H55.01: they are not reported together with it, unless the two conditions are unrelated.
- Q15 Other congenital malformations of eyecongenital nystagmus (H55.01)
Excludes2 1
These codes carry an Excludes2 note naming H55.01: its condition is not part of those codes, and both may be reported when the patient has both.
- Block H49-H52 Disorders of ocular muscles, binocular movement, accommodation and refractionnystagmus and other irregular eye movements (H55) names H55, which includes this code
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
congenital H55.01
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Nystagmus, Congenital
nystagmus present at birth or caused by lesions sustained in utero or at the time of birth. it is usually pendular, and is associated with albinism and conditions characterized by early loss of central vision. inheritance patterns may be x-linked, autosomal dominant, or recessive. (adams et al., principles of neurology, 6th ed, p275)
Patient EducationClinical
Eye Movement Disorders
When you look at an object, you're using several muscles to move both eyes to focus on it. If you have a problem with the muscles, the eyes don't work properly.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert H55.01 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About H55.01Overview
What is the ICD-10 code for congenital nystagmus?
The ICD-10-CM code for congenital nystagmus is H55.01 (sometimes written as H5501). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is H55.01 (Nystagmus) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report congenital nystagmus on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does H55.01 group to?
When congenital nystagmus is the principal diagnosis on an inpatient stay, it groups to MS-DRG 125, 124, with relative weights from 0.7699 to 1.2470 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of H55.01?
Under the General Equivalence Mappings, congenital nystagmus converts to ICD-9-CM 379.51 (congenital nystagmus). The mapping is a direct match.
