2027 ICD-10-CM Diagnosis Code H55.09Other forms of nystagmus

ICD-10-CM Codes›H00–H59›H55-H57›H55

ICD-10-CM H55.09
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

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

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 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
  • Vestibular nystagmus
  • Voluntary nystagmus

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to H55.09: 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.

From Chapter 7 (H00-H59) Diseases of the eye and adnexa applies to 2,677 codes
  • 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.

From Chapter 7 (H00-H59) Diseases of the eye and adnexa applies to 2,677 codes
  • 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 H55.09, its category, or a range that includes it.

Applicable To 1

These notes mention H55.09.

  • Z83.51 Family history of eye disorders
    Conditions classifiable to H00-H53, H55-H59 names H55-H59, which includes this code

Excludes2 1

These codes carry an Excludes2 note naming H55.09: 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 refraction
    nystagmus 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.

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

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About H55.09Overview

What is the ICD-10 code for other forms of nystagmus?

The ICD-10-CM code for other forms of nystagmus is H55.09 (sometimes written as H5509). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

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 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 H55.09?

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.