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ICD-10-CM 2027 diagnosis code

H40Glaucoma

Not billable — use a more specific code

H40 is a header code, so it can't be reported by itself. Choose one of the 9 more specific codes beneath it.

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

H40 is the ICD-10-CM diagnosis code for glaucoma. It belongs to block H40-H42 (glaucoma) and chapter 7 (diseases of the eye and adnexa). It is a header code, so it can't be reported by itself; one of its 9 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: H40.0 (suspect), H40.1 (glaucoma), H40.2 (glaucoma), H40.3 (secondary to eye trauma), H40.4 (secondary to eye inflammation), H40.5 (secondary to other eye disorders), H40.6 (secondary to drugs), H40.8 (glaucoma) and 1 more.

Don't report H40 together with the conditions in its Excludes1 note: absolute glaucoma (H44.51-), congenital glaucoma (Q15.0) and traumatic glaucoma due to birth injury (P15.3).

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

Specific codes under H40

Coding notes

Excludes1Not coded here — never report together with this code
  • absolute glaucoma (H44.51-)
  • congenital glaucoma (Q15.0)
  • traumatic glaucoma due to birth injury (P15.3)

Notes that apply from higher levels

Instructions written at a parent level also apply to H40.

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

Codes whose notes reference H40

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

Is H40 billable?

No. H40 is a header code. Report one of its more specific subcodes instead.