ICD-10 Code H16.321 – Diffuse interstitial keratitis, right eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H16.321 – Diffuse interstitial keratitis, right eye
What it is
H16.321 identifies diffuse interstitial keratitis affecting the right eye. It refers to inflammation and scarring within the corneal stroma, not the surface epithelium.
Clinical signs
Common findings include corneal haze, stromal inflammation, and reduced visual clarity in the right eye. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents diffuse interstitial keratitis specifically in the right eye. It is appropriate when the record identifies corneal stromal inflammation without a more specific alternative diagnosis. If laterality is not stated, check documentation before coding.
Do not use for
Do not use this code for keratitis limited to the left eye, both eyes, or unspecified laterality. Do not assign it for other corneal disorders unless interstitial keratitis is explicitly documented.
Coding tip
Confirm the eye laterality and the exact term “diffuse interstitial keratitis” before assigning H16.321.