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ICD-10-CM 2027 diagnosis code

H40.9Unspecified glaucoma

✓ Billable / specific

H40.9 is a valid, billable ICD-10-CM code for unspecified glaucoma. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Looking up by condition? See ICD-10 code for Glaucoma.

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 H40.9

H40.9 is the ICD-10-CM diagnosis code for unspecified glaucoma. It belongs to category H40 (glaucoma), 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.

Within H40, choose H40.9 (Unspecified glaucoma) only when documentation doesn't support a more specific option: suspect (H40.0), open-angle glaucoma (H40.1), primary angle-closure glaucoma (H40.2), secondary to eye trauma (H40.3), secondary to eye inflammation (H40.4), secondary to other eye disorders (H40.5), secondary to drugs (H40.6) and other glaucoma (H40.8).

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 365.9 (unspecified glaucoma).

Notes that apply from higher levels

Instructions written at a parent level also apply to H40.9.

› From H40 Glaucoma
Excludes1
  • absolute glaucoma (H44.51-)
  • congenital glaucoma (Q15.0)
  • traumatic glaucoma due to birth injury (P15.3)

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

Alphabetic index entries

1 entries

Terms in the official ICD-10-CM index that lead to H40.9.

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 →
  • 365.9Unspecified glaucomaexact

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 H40.9

Is H40.9 billable?

Yes. H40.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can H40.9 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict H40.9 as a principal diagnosis.

Is H40.9 a CC or MCC?

No. H40.9 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does H40.9 group to?

H40.9 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 H40.9?

The CMS General Equivalence Mappings map H40.9 to ICD-9-CM 365.9.