ICD-10 Code H18.40 – Unspecified corneal degeneration (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H18.40 – Unspecified corneal degeneration
What it is
This code identifies a corneal degeneration when the record does not specify the exact type. Use it for noninflammatory corneal tissue changes documented as degeneration, but not further described.
Clinical signs
Findings may include corneal opacity, thinning, deposits, or surface irregularity. Clinical features vary; refer to documentation for the exact degenerative pattern.
When to use this code
Use H18.40 when the provider documents corneal degeneration but does not name a specific subtype such as band-shaped, lipid, or Salzmann-type degeneration. It also fits when the chart confirms a degenerative corneal disorder and the details are unavailable. Check documentation before assigning a more specific code.
Do not use for
Do not use this code for corneal dystrophies, inflammatory keratitis, or corneal scarring from injury or infection. If the record names a specific degeneration, code that condition instead.
Coding tip
Query the provider if the note says only “corneal degeneration” and a more specific type may be supported.