Skip to content
Dx

ICD-10-CM 2027 diagnosis code

H42Glaucoma in diseases classified elsewhere

✓ Billable / specificManifestation — not principal

H42 is a valid, billable ICD-10-CM code for glaucoma in diseases classified elsewhere. 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 H42

H42 is the ICD-10-CM diagnosis code for glaucoma in diseases classified elsewhere. It belongs to block H40-H42 (glaucoma) 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.

Don't report H42 together with the conditions in its Excludes1 note: glaucoma (in) onchocerciasis (B73.02), glaucoma (in) syphilis (A52.71), glaucoma (in) tuberculous (A18.59) and neovascular secondary angle closure glaucoma (H40.84-).

Code first underlying condition, such as: amyloidosis (E85.-), aniridia (Q13.1), glaucoma (in) diabetes mellitus (E08.39, E09.39, E10.39, E11.39, E13.39), Lowe's syndrome (E72.03) and 2 more.

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 is a manifestation code, so it describes the effect of an underlying disease and can't be the principal diagnosis. Code the underlying condition first.

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 365.44 (glaucoma associated with systemic syndromes).

Coding notes

Excludes1Not coded here — never report together with this code
  • glaucoma (in) onchocerciasis (B73.02)
  • glaucoma (in) syphilis (A52.71)
  • glaucoma (in) tuberculous (A18.59)
  • neovascular secondary angle closure glaucoma (H40.84-)
Code firstSequence the underlying condition first

Notes that apply from higher levels

Instructions written at a parent level also apply to H42.

Broader instructions also apply from Chapter 7: Diseases of the eye and adnexa.

Codes whose notes reference H42

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 →
  • 365.44Glaucoma associated with systemic syndromesapproximate

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 H42

Is H42 billable?

Yes. H42 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can H42 be used as a principal diagnosis?

No. It is a manifestation code, so it describes the effect of an underlying disease and can't be the principal diagnosis. Code the underlying condition first.

Is H42 a CC or MCC?

No. H42 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does H42 group to?

H42 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 H42?

The CMS General Equivalence Mappings map H42 to ICD-9-CM 365.44.