2026 ICD-10-CM Diagnosis Code H33.101Unspecified retinoschisis, right eye

ICD-10-CM Codes›H00–H59›H30-H36›H33

ICD-10-CM H33.101
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

H33.101 is a billable ICD-10-CM diagnosis code for unspecified retinoschisis, right eye. 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. Coders also document this condition as schisis of right retina. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Retinal and vitreous conditions.

Code Identity

ICD-10-CM Code
H33.101
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified retinoschisis, right eye
Short Description
Unspecified retinoschisis, right eye
Same as the full description in the CMS dataset.
Parent Code
H33.10
Unspecified retinoschisis

Code Classification

ChapterH00–H59Diseases of the eye and adnexa
SectionH30-H36Disorders of choroid and retina
CategoryH33Retinal detachments and breaks
This CodeH33.101Unspecified retinoschisis, right eye

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Schisis of right retina

Clinical ClassificationClinical

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

CCSR EYE005
Retinal and vitreous conditions
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Retinoschisis

    a vitreoretinal dystrophy characterized by splitting of the neuroretinal layers. it occurs in two forms: degenerative retinoschisis and x chromosome-linked juvenile retinoschisis.

  • Retinoschisin|RS1|X-Linked Juvenile Retinoschisis Protein

    retinoschisin (224 aa, ~26 kda) is encoded by the human rs1 gene. this protein is involved in retinal development and aging, and may play a role in cell-cell adhesion.

  • RS1 wt Allele|RS|Retinoschisin 1 wt Allele|Retinoschisis (X-Linked, Juvenile) 1 Gene|XLRS1

    human rs1 wild-type allele is located in the vicinity of xp22.13 and is approximately 32 kb in length. this allele, which encodes retinoschisin protein, plays roles in retinal development and aging, and may have a role in cell-cell adhesion. mutations in this gene are associated with x-linked juvenile retinoschisis.

  • Juvenile X-Linked Retinoschisis

    a genetic disorder affecting primarily males. it is caused by mutations of the xlrs1 gene mapped to chromosome xp22. it affects the cells of the retina, resulting in retinal degeneration and poor eyesight.

  • Retinoschisin Protein|X-Linked Juvenile Retinoschisis Protein

    retinoschisin protein (224 aa, 26 kda) is a development protein that is encoded by the human rs1 gene and is involved in retinal development and aging, and may play a role in cell-cell adhesion.

  • Retinoschisis

    an inherited or acquired disorder characterized by splitting of the retina into two layers. it results in loss of vision.

  • RS1 Gene|RS1|RS1|Retinoschisis (X-Linked, Juvenile) 1 Gene

    this gene is involved in development, aging, and cell-cell adhesion in the retina.

  • RS1 wt Allele|Retinoschisis (X-Linked, Juvenile) 1 wt Allele

    human rs1 wild-type allele is located within xp22.2-p22.1 and is approximately 32 kb in length. this allele, which encodes retinoschisin protein, plays roles in retinal development and aging, and may have a role in cell-cell adhesion. mutations in this gene are associated with x-linked juvenile retinoschisis.

Patient EducationClinical

Retinal Disorders

The retina is a layer of tissue in the back of your eye that senses light and sends images to your brain. In the center of this nerve tissue is the macula. It provides the sharp, central vision needed for reading, driving and seeing fine detail.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert H33.101 to ICD-9-CMHistory

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

ICD-9-CM
361.10 Retinoschisis NOS
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 H33.101Overview

Is H33.101 (Unspecified retinoschisis) a billable code?

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

What MS-DRG does H33.101 group to?

When unspecified retinoschisis, right eye 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 H33.101?

Under the General Equivalence Mappings, unspecified retinoschisis, right eye converts to ICD-9-CM 361.10 (retinoschisis NOS). 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.