2026 ICD-10-CM Diagnosis Code H21.1X2Other vascular disorders of iris and ciliary body, left eye

ICD-10-CM Codes›H00–H59›H15-H22›H21

ICD-10-CM H21.1X2
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

H21.1X2 is a billable ICD-10-CM diagnosis code for other vascular disorders of iris and ciliary body, left 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified eye disorders.

Code Identity

ICD-10-CM Code
H21.1X2
Billable Status
Yes — Valid for Submission
Code Describes
Other vascular disorders of iris and ciliary body, left eye
Short Description
Other vascular disorders of iris and ciliary body, left eye
Same as the full description in the CMS dataset.
Parent Code
H21.1X
Other vascular disorders of iris and ciliary body

Code Classification

ChapterH00–H59Diseases of the eye and adnexa
SectionH15-H22Disorders of sclera, cornea, iris and ciliary body
CategoryH21Other disorders of iris and ciliary body
This CodeH21.1X2Other vascular disorders of iris and ciliary body, left eye

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute angle closure of left eye due to neovascularization
  • Angle closure of left eye due to neovascularization
  • Neovascular angle closure glaucoma
  • Neovascular angle closure glaucoma of left eye
  • Neovascularization of angle of left eye
  • Neovascularization of inferior quadrant of angle
  • Neovascularization of inferior quadrant of angle of left eye
  • Neovascularization of nasal quadrant of angle
  • Neovascularization of nasal quadrant of angle of left eye
  • Neovascularization of superior quadrant of angle
  • Neovascularization of superior quadrant of angle of left eye
  • Neovascularization of temporal quadrant of angle
  • Neovascularization of temporal quadrant of angle of left eye
  • Open angle glaucoma of left eye due to neovascularization
  • Rubeosis iridis
  • Rubeosis iridis of left eye
  • Secondary acute angle closure due to neovascularization
  • Secondary angle closure due to neovascularization
  • Secondary open angle glaucoma due to neovascularization

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 Diseases

Even if your eyes feel healthy, you could have a problem and not know it. That's why regular eye exams are so important. Refractive errors are the most common type of vision problem that makes it hard to see clearly. But some eye conditions or diseases don't have any symptoms and can lead to a permanent loss of vision.

The full article covers:

  • What diseases can affect the eye?
  • What are the symptoms of eye diseases?
  • Who is more likely to develop eye diseases?
  • What are the treatments for eye diseases?
  • Can eye diseases be prevented?

Read the full article at MedlinePlus

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

Convert H21.1X2 to ICD-9-CMHistory

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

ICD-9-CM
364.42 Rubeosis iridis
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 H21.1X2Overview

Is H21.1X2 (Other vascular disorders of iris and ciliary body) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other vascular disorders of iris and ciliary body, left eye on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does H21.1X2 group to?

When other vascular disorders of iris and ciliary body, left 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 H21.1X2?

Under the General Equivalence Mappings, other vascular disorders of iris and ciliary body, left eye converts to ICD-9-CM 364.42 (rubeosis iridis). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.