ICD-10 Code H40.039 – Anatomical narrow angle, unspecified eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H40.039 – Anatomical narrow angle, unspecified eye
What it is
This code identifies a narrow anterior chamber angle in the eye when the side is not specified. It indicates an anatomic finding that can increase the risk of angle-closure glaucoma.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include a narrow or occludable angle on gonioscopy, with or without symptoms of angle narrowing.
When to use this code
Use H40.039 when the provider documents anatomical narrow angle but does not specify right or left eye. This is appropriate for screening, evaluation, or follow-up notes that describe the angle anatomy without confirmed glaucoma. If documentation names laterality, code that specific option instead.
Do not use for
Do not use this code for documented angle-closure glaucoma or for a specified right or left eye code. Check documentation if the record describes a different glaucoma type or a more specific eye laterality.
Coding tip
Verify laterality and whether glaucoma is actually diagnosed before assigning H40.039.