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ICD-10-CM 2027 diagnosis code

H05.021Osteomyelitis of right orbit

✓ Billable / specificCC — complication/comorbidity

H05.021 is a valid, billable ICD-10-CM code for osteomyelitis of right orbit. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About H05.021

H05.021 is the ICD-10-CM diagnosis code for osteomyelitis of right orbit. It belongs to category H05 (disorders of orbit), block H00-H05 (disorders of eyelid, lacrimal system and orbit) and chapter 7 (diseases of the eye and adnexa). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within H05.02 (osteomyelitis of orbit), H05.021 is specifically for osteomyelitis of right orbit. Related codes cover left orbit (H05.022), bilateral orbits (H05.023) and unspecified orbit (H05.029).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 121 (Acute Major Eye Infections with CC/MCC, relative weight 1.2255) and DRG 122 (Acute Major Eye Infections without CC/MCC, relative weight 0.7406), in MDC 02 (Diseases and Disorders of the Eye), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 376.03 (orbital osteomyelitis).

Notes that apply from higher levels

Instructions written at a parent level also apply to H05.021.

› From H05 Disorders of orbit
Excludes1
  • congenital malformation of orbit (Q10.7)

Broader instructions also apply from H00-H05 Disorders of eyelid, lacrimal system and orbit and Chapter 7: Diseases of the eye and adnexa.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 376.03Orbital osteomyelitisapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about H05.021

Is H05.021 billable?

Yes. H05.021 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can H05.021 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict H05.021 as a principal diagnosis.

Is H05.021 a CC or MCC?

H05.021 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.

What DRG does H05.021 group to?

H05.021 is used in the MS-DRG v44.0 logic for MS-DRG 121 (Acute Major Eye Infections with CC/MCC) and MS-DRG 122 (Acute Major Eye Infections without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for H05.021?

The CMS General Equivalence Mappings map H05.021 to ICD-9-CM 376.03.