ICD-10 Code H40.009 – Preglaucoma, unspecified, unspecified eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H40.009 – Preglaucoma, unspecified, unspecified eye
What it is
This code identifies a preglaucoma condition in an unspecified eye, meaning the chart suggests increased glaucoma risk but does not name a specific eye or subtype. Use it when documentation is limited and the diagnosis is not more precise.
Clinical signs
Clinical features vary; refer to documentation. Findings may include suspicious optic nerve changes, elevated or borderline intraocular pressure, or other glaucoma risk indicators without confirmed glaucoma.
When to use this code
Use H40.009 when the provider documents preglaucoma but does not specify laterality or a more exact diagnosis. It also fits when the record notes glaucoma-suspect findings and the eye is not identified. If the note supports a different glaucoma diagnosis, code that instead.
Do not use for
Do not use this code for confirmed glaucoma, ocular hypertension, or a clearly documented glaucoma subtype. If the eye is specified, or if documentation is more precise, choose the appropriate more specific code.
Coding tip
Check the ophthalmology note for laterality and whether the provider meant preglaucoma, glaucoma suspect, or confirmed glaucoma.