ICD-10 Code H40.032 – Anatomical narrow angle, left eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H40.032 – Anatomical narrow angle, left eye
What it is
This code identifies a narrow anterior chamber angle in the left eye due to anatomy. It indicates a structural predisposition to impaired aqueous outflow and possible angle-closure glaucoma.
Clinical signs
Findings may include a shallow anterior chamber and a narrow or occludable angle on gonioscopy. Clinical features vary; refer to documentation.
When to use this code
Use H40.032 when the provider documents anatomical narrow angle specifically in the left eye. It is appropriate for confirmed anatomic narrowing, even if glaucoma is not yet diagnosed. Use the laterality exactly as documented.
Do not use for
Do not use this code for open-angle glaucoma, acute angle-closure episodes, or unspecified laterality. If the note does not clearly identify the left eye, check documentation.
Coding tip
Code the documented eye and avoid assuming glaucoma unless the record states it.