2026 ICD-10-CM Diagnosis Code H21.81Floppy iris syndrome

ICD-10-CM Codes›H00–H59›H15-H22›H21

ICD-10-CM H21.81
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

H21.81 is a billable ICD-10-CM diagnosis code for floppy iris syndrome. 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
H21.81
Billable Status
Yes — Valid for Submission
Code Describes
Floppy iris syndrome
Short Description
Floppy iris syndrome
Same as the full description in the CMS dataset.
Parent Code
H21.8
Other specified 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 CodeH21.81Floppy iris syndrome

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bilateral intraoperative floppy iris syndrome
  • Intraoperative floppy iris syndrome
  • Intraoperative floppy iris syndrome following administration of tamsulosin
  • Intraoperative floppy iris syndrome of left eye
  • Intraoperative floppy iris syndrome of right eye

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Intraoperative floppy iris syndrome (IFIS)

Use Additional Code

  • code for adverse effect, if applicable, to identify drug T36 T50

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.

    • Floppy
      • iris syndrome (intraoperative) (IFIS)
    • Syndrome
      • floppy
        • iris (intraoeprative) (IFIS)

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 H21.81 to ICD-9-CMHistory

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

ICD-9-CM
364.81 Floppy iris syndrome
Exact Match The mapping is direct, with no qualifiers.

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 H21.81Overview

Is H21.81 (Other specified disorders of iris and ciliary body) a billable code?

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

What MS-DRG does H21.81 group to?

When floppy iris syndrome 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 H21.81?

Under the General Equivalence Mappings, floppy iris syndrome converts to ICD-9-CM 364.81 (floppy iris syndrome). The mapping is a direct match.

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.