ICD-10 Code H18.502 – Unspecified hereditary corneal dystrophies, left eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H18.502 – Unspecified hereditary corneal dystrophies, left eye
What it is
This code identifies a hereditary corneal dystrophy affecting the left eye when the exact type is not specified. It indicates a genetic corneal disorder, but the documentation does not name a more precise dystrophy.
Clinical signs
Clinical features vary; refer to documentation. Common findings in corneal dystrophy include corneal opacity, visual disturbance, glare, or recurrent corneal surface changes, but you should code only what is documented.
When to use this code
Use H18.502 when the provider documents an inherited corneal dystrophy in the left eye and does not identify the subtype. It also fits when the record confirms a hereditary corneal dystrophy but leaves the diagnosis unspecified. If the type is named, choose the more specific code.
Do not use for
Do not use this code for acquired corneal disease, bilateral disease coded elsewhere, or a specified hereditary corneal dystrophy. Check documentation if the eye laterality or exact dystrophy type is unclear.
Coding tip
Confirm both laterality and whether the dystrophy is hereditary before assigning H18.502.