ICD-10-CM 2027 diagnosis code
H11.421Conjunctival edema, right eye
H11.421 is a valid, billable ICD-10-CM code for conjunctival edema, right eye. 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 H11.421
H11.421 is the ICD-10-CM diagnosis code for conjunctival edema, right eye. It belongs to category H11 (other disorders of conjunctiva), block H10-H11 (disorders of conjunctiva) 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 H11.42 (conjunctival edema), H11.421 is specifically for conjunctival edema, right eye. Related codes cover left eye (H11.422), bilateral (H11.423) and unspecified eye (H11.429).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 124 (Other Disorders of the Eye with MCC or Thrombolytic Agent, relative weight 1.2471) and DRG 125 (Other Disorders of the Eye without MCC, relative weight 0.7702), 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 372.73 (conjunctival edema).
Notes that apply from higher levels
Instructions written at a parent level also apply to H11.421.
› From H11 Other disorders of conjunctiva
- keratoconjunctivitis (H16.2-)
Broader instructions also apply from 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.
MDC 02 · Diseases and Disorders of the Eye
ICD-9-CM equivalent
Converter →- 372.73Conjunctival edemaapproximate
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about H11.421
Is H11.421 billable?
- Yes. H11.421 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can H11.421 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict H11.421 as a principal diagnosis.
Is H11.421 a CC or MCC?
- No. H11.421 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does H11.421 group to?
- H11.421 is used in the MS-DRG v44.0 logic for MS-DRG 124 (Other Disorders of the Eye with MCC or Thrombolytic Agent) and MS-DRG 125 (Other Disorders of the Eye without 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 H11.421?
- The CMS General Equivalence Mappings map H11.421 to ICD-9-CM 372.73.