ICD-10 Code H16.3 – Interstitial and deep keratitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H16.3 – Interstitial and deep keratitis
What it is
H16.3 identifies keratitis affecting the deeper corneal layers, including interstitial inflammation. Use it when documentation specifies deep or interstitial corneal involvement rather than a superficial corneal disorder.
Clinical signs
Typical findings may include corneal haze, stromal inflammation, pain, photophobia, and reduced vision. Clinical features vary; refer to documentation when the record does not clearly describe the depth or cause of keratitis.
When to use this code
Use H16.3 when the provider documents interstitial keratitis, deep keratitis, or stromal corneal inflammation. It also fits when the note clearly distinguishes the condition from superficial keratitis or corneal abrasion. If the chart only says “keratitis” without depth, check documentation.
Do not use for
Do not use this code for superficial keratitis, corneal ulcer, or nonspecific eye irritation. If the diagnosis is another corneal disorder or the record is unclear, check documentation.
Coding tip
Code H16.3 only when the documentation supports deep or interstitial corneal involvement; otherwise, query for a more specific diagnosis.