H40.001 Preglaucoma, unspecified, right eye

Billable ICD-10-CM code, FY2026.

Applies from H40 Glaucoma

Excludes1 (never code together)

• absolute glaucoma (H44.51-)
• congenital glaucoma (Q15.0)
• traumatic glaucoma due to birth injury (P15.3)

MS-DRG index

Defines the logic of DRG(s) 124-125 in MDC 02.

Approximate ICD-9-CM (GEMs)

• 365.00 Preglaucoma, unspecified (approximate)

Code annotations containing back-references to H40.001

Back-references to H40

• Use Additional: E08.39 Diabetes mellitus due to underlying condition with other diabetic ophthalmic complication ("diabetic glaucoma (H40-H42)")
• Use Additional: E09.39 Drug or chemical induced diabetes mellitus with other diabetic ophthalmic complication ("diabetic glaucoma (H40-H42)")
• Use Additional: E10.39 Type 1 diabetes mellitus with other diabetic ophthalmic complication ("diabetic glaucoma (H40-H42)")
• Use Additional: E11.39 Type 2 diabetes mellitus with other diabetic ophthalmic complication ("diabetic glaucoma (H40-H42)")
• Use Additional: E13.39 Other specified diabetes mellitus with other diabetic ophthalmic complication ("diabetic glaucoma (H40-H42)")
• Code First: H26.23 Glaucomatous flecks (subcapsular) ("underlying glaucoma (H40-H42)")

Nearby codes

• H40 Glaucoma
• H40.0 Glaucoma suspect
• H40.00 Preglaucoma, unspecified
• H40.001 Preglaucoma, unspecified, right eye (this code)
• H40.002 Preglaucoma, unspecified, left eye
• H40.003 Preglaucoma, unspecified, bilateral
• H40.009 Preglaucoma, unspecified, unspecified eye
• H40.01 Open angle with borderline findings, low risk
• H40.011 Open angle with borderline findings, low risk, right eye