H40.9 — Unspecified glaucoma

H40.9

ICD-10 Chapter 7: Eye & Adnexa — illustrative image — Chapter 7: Diseases of the eye and adnexa (H00–H59) — illustrative image

What this code means

Glaucoma is a group of eye conditions in which the optic nerve is damaged, usually by raised pressure inside the eye.

Also called: glaucoma.

When this code is used

Used for glaucoma when the type is not specified.

Where it sits in ICD-10-CM

Code H40.9 belongs to Chapter 7: Diseases of the eye and adnexa, which covers codes H00–H59 in the FY2027 ICD-10-CM tabular list. The official description above is copied verbatim from the CDC/NCHS FY2027 code file.

Related anatomy

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Frequently asked questions

What is ICD-10-CM code H40.9?

H40.9 is the ICD-10-CM diagnosis code for “Unspecified glaucoma”. Glaucoma is a group of eye conditions in which the optic nerve is damaged, usually by raised pressure inside the eye.

When is code H40.9 used?

Used for glaucoma when the type is not specified. It belongs to Chapter 7 of ICD-10-CM (Diseases of the eye and adnexa).

This guide explains ICD-10-CM codes in plain language for patients, students and other readers. It is educational information only — not coding, billing or medical advice. The code recorded for any real encounter is assigned from the full clinical documentation by the treating team and qualified coders, and only they can decide which code fits a specific case.