2026 ICD-10-CM Diagnosis Code H21.561Pupillary abnormality, right eye

ICD-10-CM Codes›H00–H59›H15-H22›H21

ICD-10-CM H21.561
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

H21.561 is a billable ICD-10-CM diagnosis code for pupillary abnormality, 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 disorder of sphincter pupillae muscle. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified eye disorders.

Code Identity

ICD-10-CM Code
H21.561
Billable Status
Yes — Valid for Submission
Code Describes
Pupillary abnormality, right eye
Short Description
Pupillary abnormality, right eye
Same as the full description in the CMS dataset.
Parent Code
H21.56
Pupillary abnormalities

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 CodeH21.561Pupillary abnormality, right eye

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Disorder of sphincter pupillae muscle
  • Disruption of iris
  • Injury of sphincter pupillae muscle
  • Pupillary block
  • Pupillary block of right eye
  • Right secondary angle-closure glaucoma due to pupil block
  • Rupture of sphincter of pupil
  • Rupture of sphincter of pupil of right eye
  • Secondary angle-closure glaucoma with pupillary block

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

  • Pupillary Block

    an obstruction of the pupil.

Patient EducationClinical

Eye Diseases

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The full article covers:

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Read the full article at MedlinePlus

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

Convert H21.561 to ICD-9-CMHistory

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

ICD-9-CM
364.75 Pupillary abnormalities
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 H21.561Overview

Is H21.561 (Pupillary abnormalities) a billable code?

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

What MS-DRG does H21.561 group to?

When pupillary abnormality, 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 H21.561?

Under the General Equivalence Mappings, pupillary abnormality, right eye converts to ICD-9-CM 364.75 (pupillary abnormalities). 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.