H18.612 Keratoconus, stable, left eye

ICD-10-CM H18.612: Keratoconus, stable, left eye

ICD-10-CM code H18.612 identifies stable keratoconus in the left eye, functioning as a billable diagnosis with an active status. It exists within a broader coding hierarchy that separates stable keratoconus from unspecified or unstable variants, and it appears in payer contexts like corneal pachymetry billing articles. 1 3 6

Plain-language overview

Keratoconus is classified as a disease or syndrome, and the specific code for stable keratoconus in the left eye is currently designated with an active terminology record status. 1

What this code represents

The diagnosis code H18.612 represents the specific condition of stable keratoconus affecting the left eye, distinguishing it from unspecified or unstable forms of the same condition. 4 5

Code H18.612 is a billable, specific diagnosis code valid for reimbursement purposes, and it falls under the parent concept of stable keratoconus generally. 1 6

Coding details

The broader category for this diagnosis includes distinct codes for stable, unstable, and unspecified keratoconus, with H18.612 specifically capturing the stable left eye presentation. 4

While H18.612 denotes a stable condition, separate codes exist for unstable left eye keratoconus, and the terminology record confirms H18.612 has narrower related concepts. 1 5

Documentation considerations

Clinical literature notes that keratoconus treatment is largely dependent on disease severity, and the lack of well-defined diagnostic criteria contributes to high variability in reported prevalence. 2

Coverage and utilization context

Code H18.612 is listed in a Medicare billing and coding article for corneal pachymetry alongside the bilateral stable keratoconus code, and the article references annual ICD-10-CM updates. 3

What the sources add

Clinical literature indicates that scleral lenses provide sustained visual acuity improvements for keratoconus patients, while coding sources establish the specific structural hierarchy for the H18.612 diagnosis. 1 2

A clinical reference outlines a full list of keratoconus codes separating right, left, bilateral, and unspecified eyes, whereas a payer article specifically lists H18.612 alongside bilateral stable keratoconus. 3 4

Sources

1. ICD-10-CM H18.612 terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Long-Term Effectiveness of Scleral Lens Treatment in the Management of Keratoconus: A Systematic Review — pmc.ncbi.nlm.nih.gov; accessed 2026-07-27.
3. Article - Billing and Coding: Corneal Pachymetry (A56548) — cms.gov; accessed 2026-07-27.
4. ICD-10 CM — point32health.org; accessed 2026-07-27.
5. ICD-10-CM 2024 | H18.6 - Keratoconus — unboundmedicine.com; accessed 2026-07-27.
6. H18.612 — Keratoconus, stable, left eye | ICD-10 Code · Eleplan — eleplan.com; accessed 2026-07-27.