2026 ICD-10-CM Diagnosis Code H55.00Unspecified nystagmus
ICD-10-CM Codes›H00–H59›H55-H57›H55
- Billable — Valid for Submission
- Not Chronic
H55.00 is a billable ICD-10-CM diagnosis code for unspecified nystagmus. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). 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.
- Acquired nystagmus
- Essential tremor
- Eyelid nystagmus
- Hereditary essential tremor
- Idiopathic nystagmus
- Irregular nystagmus
- Manifest nystagmus
- Nystagmus
- Nystagmus and other irregular eye movements
- Nystagmus inhibited when fixation removed
- Nystagmus present
- Nystagmus signs
- Nystagmus unchanged when fixation removed
- Permanent nystagmus
- Physiological nystagmus
- Rotational nystagmus
- Tremor, nystagmus, duodenal ulcer syndrome
- Uniocular nystagmus
- Uniocular nystagmus of left eye
- Uniocular nystagmus of right eye
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Nystagmus - H55.00
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Nystagmus
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Essential Tremor
a relatively common disorder characterized by a fairly specific pattern of tremors which are most prominent in the upper extremities and neck, inducing titubations of the head. the tremor is usually mild, but when severe may be disabling. an autosomal dominant pattern of inheritance may occur in some families (i.e., familial tremor). (mov disord 1988;13(1):5-10)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.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.Essential Tremor
a movement disorder characterized by involuntary and rhythmic shaking of parts of the body, most often the hands or arms, that can be triggered or worsened by physical or environmental stressors. essential tremor may be progressive and can be inherited in an autosomal dominant manner.
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 H55.00 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About H55.00Overview
Is H55.00 (Nystagmus) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified nystagmus on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What is the ICD-9 equivalent of H55.00?
Under the General Equivalence Mappings, unspecified nystagmus converts to ICD-9-CM 379.50 (nystagmus NOS). 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.
