2026 ICD-10-CM Diagnosis Code H05.021Osteomyelitis of right orbit

ICD-10-CM Codes›H00–H59›H00-H05›H05

ICD-10-CM H05.021
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

H05.021 is a billable ICD-10-CM diagnosis code for osteomyelitis of right orbit. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 121 through 122. Coders also document this condition as infection of orbit. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Oculofacial plastics and orbital conditions and Osteomyelitis.

Code Identity

ICD-10-CM Code
H05.021
Billable Status
Yes — Valid for Submission
Code Describes
Osteomyelitis of right orbit
Short Description
Osteomyelitis of right orbit
Same as the full description in the CMS dataset.
Parent Code
H05.02
Osteomyelitis of orbit

Code Classification

ChapterH00–H59Diseases of the eye and adnexa
SectionH00-H05Disorders of eyelid, lacrimal system and orbit
CategoryH05Disorders of orbit
This CodeH05.021Osteomyelitis of right orbit

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Infection of orbit
  • Orbital osteomyelitis
  • Osteomyelitis of nasal-orbit complex
  • Osteomyelitis of orbit of right eye

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
CCSR MUS002
Osteomyelitis
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Bone Infections

Like other parts of the body, bones can get infected. The infections are usually bacterial, but can also be fungal. They may spread to the bone from nearby skin or muscles, or from another part of the body through the bloodstream.

Read the full article at MedlinePlus

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

Convert H05.021 to ICD-9-CMHistory

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

ICD-9-CM
376.03 Orbital osteomyelitis
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 H05.021Overview

Is H05.021 (Osteomyelitis of orbit) a billable code?

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

What MS-DRG does H05.021 group to?

When osteomyelitis of right orbit is the principal diagnosis on an inpatient stay, it groups to MS-DRG 121, 122, with relative weights from 0.7858 to 1.1633 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of H05.021?

Under the General Equivalence Mappings, osteomyelitis of right orbit converts to ICD-9-CM 376.03 (orbital osteomyelitis). 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.