2026 ICD-10-CM Diagnosis Code H55.04Dissociated nystagmus

ICD-10-CM Codes›H00–H59›H55-H57›H55

ICD-10-CM H55.04
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

H55.04 is a billable ICD-10-CM diagnosis code for dissociated nystagmus. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as abducting nystagmus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified eye disorders.

Code Identity

ICD-10-CM Code
H55.04
Billable Status
Yes — Valid for Submission
Code Describes
Dissociated nystagmus
Short Description
Dissociated nystagmus
Same as the full description in the CMS dataset.
Parent Code
H55.0
Nystagmus

Code Classification

ChapterH00–H59Diseases of the eye and adnexa
SectionH55-H57Other disorders of eye and adnexa
CategoryH55Nystagmus and other irregular eye movements
This CodeH55.04Dissociated nystagmus

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abducting nystagmus
  • Dissociated nystagmus

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Nystagmus
      • dissociated

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR EYE012
Other specified eye disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Grade 2 Nystagmus, CTCAE|Grade 2 Nystagmus|Grade 2 Nystagmus

    moderate symptoms; limiting instrumental adl

  • Grade 3 Nystagmus, CTCAE|Grade 3 Nystagmus|Grade 3 Nystagmus

    severe symptoms; limiting self care adl

  • Kurtzke 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 H55.04 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
379.55 Dissociated nystagmus
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About H55.04Overview

Is H55.04 (Nystagmus) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report dissociated nystagmus on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of H55.04?

Under the General Equivalence Mappings, dissociated nystagmus converts to ICD-9-CM 379.55 (dissociated 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.