H40.1520 Residual stage of open-angle glaucoma, left eye, stage unspecified

ICD-10-CM Code H40.1520: Residual stage of open-angle glaucoma, left eye, stage unspecified

ICD-10-CM code H40.1520 appears in an official Medicaid list of exempt diagnoses. General clinical literature indicates that glaucoma involves increased intraocular pressure that can cause optic neuropathy and vision loss, and is classified as open-angle or closed-angle. Medicare billing articles list related residual stage open-angle glaucoma codes by laterality. 2 3 4

Plain-language overview

Glaucoma is characterized by increased intraocular pressure that can result in optic neuropathy and vision loss if left untreated, and it is classified as open-angle or closed-angle. 2

Glaucoma is further classified as primary or secondary depending on the obstruction in the anterior chamber, providing context for understanding open-angle conditions. 2

What this code represents

The code H40.1520 is included in an official Medicaid document that lists ICD-10 exempt diagnoses, placing it among numerous other glaucoma codes such as H40.1510 and H40.1521. 3

Medicare billing articles list codes for the residual stage of open-angle glaucoma by eye, showing separate categories for the right eye and the left eye. 4 5

Coding details

Medicare billing articles distinguish residual stage open-angle glaucoma by laterality, listing right eye as H40.152 and left eye as H40.153 at the category level. 4 5

Documentation considerations

Clinical literature notes that identifying patients at risk for glaucoma occurs through comprehensive medical history, ocular examination, and relevant diagnostic tests. 2

Coverage and utilization context

The inclusion of H40.1520 in a Medicaid list of exempt diagnoses and Medicare billing articles places it within administrative contexts, though the texts do not specify reimbursement outcomes. 3 4

What the sources add

Clinical sources describe glaucoma as involving increased intraocular pressure causing optic neuropathy, while administrative sources list H40.1520 among other diagnosis codes. 2 3

The Medicaid source lists H40.1520 among numerous glaucoma codes, while Medicare articles provide category-level context by separating residual stage open-angle glaucoma codes by right and left eye. 3 4

Sources

1. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-27.
2. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-27.
3. Diagnosis Code — medicaid.ncdhhs.gov; accessed 2026-07-27.
4. Article - Billing and Coding: Insertion of anterior segment aqueous drainage device, without extraocular reservoir, external approach (0192T 66183) (A52432) — cms.gov; accessed 2026-07-27.
5. Article - Billing and Coding: Corneal Pachymetry (A56548) — cms.gov; accessed 2026-07-27.