Skip to content
Dx

ICD-10-CM 2027

ICD-10 code for anterior chamber angle narrow

H40.03

Anatomical narrow angle

Header — needs a more specific code

From the official ICD-10-CM alphabetic index entry “Narrow › anterior chamber angle”. Page updated September 29, 2026.

About coding anterior chamber angle narrow

The ICD-10-CM code for anterior chamber angle narrow is H40.03 (Anatomical narrow angle).

Within H40.0 (glaucoma suspect), H40.03 is specifically for anatomical narrow angle. Related codes cover Preglaucoma, unspecified (H40.00), open angle with borderline findings, low risk (H40.01), open angle with borderline findings, high risk (H40.02), steroid responder (H40.04), ocular hypertension (H40.05) and primary angle closure without glaucoma damage (H40.06).

To report this condition, pick the subcode that matches the documentation: H40.031 (right eye), H40.032 (left eye), H40.033 (bilateral) and H40.039 (unspecified eye).

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

Common questions about anterior chamber angle narrow ICD-10 codes

What is the ICD-10 code for anterior chamber angle narrow?

H40.03 — Anatomical narrow angle (a header code; report a more specific subcode).

Is H40.03 billable?

No. H40.03 is a header code. Report one of its more specific subcodes instead.