2026 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 2026 (October 1, 2025 through September 30, 2026) 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
- Spastic paraplegia, intellectual disability, nystagmus, obesity syndrome
- Syndactyly, nystagmus syndrome due to 2q31.1 microduplication
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- congenital - H55.01
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Nystagmus
- congenital
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Grade 2 Nystagmus, CTCAE|Grade 2 Nystagmus|Grade 2 Nystagmus
moderate symptoms; limiting instrumental adlGrade 3 Nystagmus, CTCAE|Grade 3 Nystagmus|Grade 3 Nystagmus
severe symptoms; limiting self care adlKurtzke Functional System Scores KFSS103 Original Result - Moderate nystagmus or other mild disability|KFSS103-Moderate nystagmus or other mild disability|Moderate nystagmus or other mild disability
kurtzke functional system scores kfss103 original result - moderate nystagmus or other mild disability.Kurtzke Functional System Scores KFSS103 Original Result - Severe nystagmus, marked extraocular weakness, or moderate disability of other cranial nerves|KFSS103-Severe nystagmus, marked extraocular weakness, or moderate disability of other cranial nerves|Severe nystagmus, marked extraocular weakness, or moderate disability of other cranial nerves
kurtzke functional system scores kfss103 original result - severe nystagmus, marked extraocular weakness, or moderate disability of other cranial nerves.Nystagmus
involuntary movements of the eyeballs. the presence or absence of nystagmus is often used in the diagnosis of a variety of neurological and visual disorders.Nystagmus, CTCAE 5.0|Nystagmus|Nystagmus
a disorder characterized by involuntary movements of the eyeballs.Acquired Jerk Nystagmus|Acquired jerk nystagmus
nystagmus that develops after birth and is characterized by a slow drift of the eyeballs in one direction followed by a fast corrective movement to the original position.Grade 2 Nystagmus, CTCAE|Grade 2 Nystagmus|Grade 2 Nystagmus
moderate symptoms; limiting instrumental adl or mild/moderate impact on age-appropriate normal daily activity (pediatric)Grade 3 Nystagmus, CTCAE|Grade 3 Nystagmus|Grade 3 Nystagmus
severe symptoms; limiting self-care adl or severe impact on age-appropriate normal daily activity (pediatric)Nystagmus Assessment
an evaluation of nystagmus (involuntary, rapid eye movement).Nystagmus, CTCAE|Nystagmus|Nystagmus|Nystagmus, CTCAE 5.0
a disorder characterized by involuntary movements of the eyeballs.
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
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, 2025 through September 30, 2026.
What MS-DRG does H55.01 group to?
When congenital nystagmus is the principal diagnosis on an inpatient stay, it groups to MS-DRG 124, 125, with relative weights from 0.7678 to 1.3231 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.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
