ICD-10 Code H18.042 – Kayser-Fleischer ring, left eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H18.042 – Kayser-Fleischer ring, left eye
What it is
This code identifies a Kayser-Fleischer ring in the left eye, a copper-colored corneal ring seen on eye exam. It reflects a documented ocular finding, not a standalone systemic diagnosis.
Clinical signs
You may see a golden-brown to greenish ring at the corneal margin, best noted on slit-lamp exam. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents a Kayser-Fleischer ring specifically in the left eye. It is appropriate for ophthalmology notes, consults, or problem lists that clearly identify laterality. If both eyes are documented, code each eye separately.
Do not use for
Do not use it for nonspecific corneal discoloration or when the eye laterality is not stated. Check documentation if the record only mentions suspected Wilson disease without confirming the ring.
Coding tip
Verify laterality in the exam note before assigning H18.042.