ICD-10 Code H16.21 – Exposure keratoconjunctivitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H16.21 – Exposure keratoconjunctivitis
What it is
H16.21 identifies keratoconjunctivitis caused by inadequate eyelid closure or another exposure problem. It describes corneal and conjunctival irritation from drying, not an infectious eye disease.
Clinical signs
Typical findings include ocular redness, foreign-body sensation, tearing, and surface dryness. Clinical features vary; refer to documentation for lagophthalmos, incomplete blink, or corneal epithelial damage.
When to use this code
Use this code when the record states exposure keratoconjunctivitis, exposure-related corneal irritation, or keratoconjunctivitis from poor lid closure. It may apply when a clinician documents exposure from facial nerve palsy, eyelid malposition, or similar causes. Check documentation for the exact cause.
Do not use for
Do not use it for infectious conjunctivitis, dry eye alone, or nonspecific eye irritation without exposure-related corneal involvement. If the chart only says “red eye,” check documentation.
Coding tip
Capture the underlying exposure cause when documented, because it may need separate coding.