2026 ICD-10-CM Diagnosis Code H05.821Myopathy of extraocular muscles, right orbit

ICD-10-CM Codes›H00–H59›H00-H05›H05

ICD-10-CM H05.821
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

H05.821 is a billable ICD-10-CM diagnosis code for myopathy of extraocular muscles, right orbit. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as dysfunction of inferior oblique muscle. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Oculofacial plastics and orbital conditions.

Code Identity

ICD-10-CM Code
H05.821
Billable Status
Yes — Valid for Submission
Code Describes
Myopathy of extraocular muscles, right orbit
Short Description
Myopathy of extraocular muscles, right orbit
Same as the full description in the CMS dataset.
Parent Code
H05.82
Myopathy of extraocular muscles

Code Classification

ChapterH00–H59Diseases of the eye and adnexa
SectionH00-H05Disorders of eyelid, lacrimal system and orbit
CategoryH05Disorders of orbit
This CodeH05.821Myopathy of extraocular muscles, right orbit

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Dysfunction of inferior oblique muscle
  • Dysfunction of inferior oblique muscle of right eye
  • Myopathy of extraocular muscle of right eye
  • Right superior oblique muscle dysfunction
  • Superior oblique dysfunction

Clinical ClassificationClinical

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

CCSR EYE008
Oculofacial plastics and orbital conditions
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

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Read the full article at MedlinePlus

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

Convert H05.821 to ICD-9-CMHistory

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

ICD-9-CM
376.82 Extraocul muscl myopathy
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 H05.821Overview

Is H05.821 (Myopathy of extraocular muscles) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report myopathy of extraocular muscles, right orbit on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of H05.821?

Under the General Equivalence Mappings, myopathy of extraocular muscles, right orbit converts to ICD-9-CM 376.82 (extraocul muscl myopathy). 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.