2026 ICD-10-CM Diagnosis Code H55.09Other forms of nystagmus

ICD-10-CM CodesH00–H59H55-H57H55

ICD-10-CM H55.09
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

H55.09 is a billable ICD-10-CM diagnosis code for other forms of 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

ICD-10-CM Code
H55.09
Billable Status
Yes — Valid for Submission
Code Describes
Other forms of nystagmus
Short Description
Other forms of nystagmus
Same as the full description in the CMS dataset.
Parent Code
Nystagmus

Code Classification

ChapterH00–H59Diseases of the eye and adnexa
SectionH55-H57Other disorders of eye and adnexa
CategoryH55Nystagmus and other irregular eye movements
This CodeH55.09Other forms of nystagmus

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acquired nystagmus
  • Acquired pendular nystagmus
  • Acquired periodic alternating nystagmus
  • Ataxic nystagmus
  • Bruns nystagmus
  • Central vestibular nystagmus
  • Centripetal nystagmus
  • Conjugate nystagmus
  • Convergence nystagmus
  • Convergence retraction nystagmus
  • Cyclovergence nystagmus
  • Disjunctive pendular nystagmus
  • Divergence retraction nystagmus
  • Elliptical nystagmus
  • End-point nystagmus
  • Fixation nystagmus
  • Gaze paretic nystagmus
  • Gaze-evoked nystagmus
  • Hemi-seesaw nystagmus
  • Hennebert's syndrome
  • Horizontal nystagmus
  • Infantile nystagmus syndrome
  • Jerk nystagmus
  • Mixed nystagmus
  • Multidirectional nystagmus
  • Non-rhythmic abnormal eye movement
  • Nystagmus associated with disorder of the vestibular system
  • Nystagmus enhanced when fixation removed
  • Nystagmus produced by neck rotation
  • Pendular nystagmus
  • Periodic alternating nystagmus
  • Peripheral vestibular nystagmus
  • Perverted nystagmus
  • Positional nystagmus
  • Positional nystagmus, variable eye direction
  • Postural nystagmus
  • Pressure-induced nystagmus
  • Rebound nystagmus
  • Retraction nystagmus
  • Rotary nystagmus
  • See-saw nystagmus
  • Sensory nystagmus
  • Sound intensity-induced nystagmus
  • Spontaneous nystagmus
  • Temporary nystagmus
  • Torsional central vestibular nystagmus
  • Torsional nystagmus
  • Unidirectional nystagmus
  • Uniocular nystagmus
  • Upbeat central vestibular nystagmus
  • Vertical nystagmus
  • Voluntary 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
      • miners'
    • Nystagmus
      • specified form NEC

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 H55.09 to ICD-9-CMHistory

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

ICD-9-CM
379.56 Nystagmus NEC
Approximate The match is approximate rather than exact.

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 H55.09Overview

Is H55.09 (Nystagmus) a billable code?

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

What MS-DRG does H55.09 group to?

When other forms of 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 H55.09?

Under the General Equivalence Mappings, other forms of nystagmus converts to ICD-9-CM 379.56 (nystagmus NEC). The mapping is approximate, so confirm the match fits the documentation.

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.