ICD-10 Code H10.421 – Simple chronic conjunctivitis, right eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H10.421 – Simple chronic conjunctivitis, right eye
What it is
H10.421 identifies chronic inflammation of the conjunctiva in the right eye, described as simple chronic conjunctivitis. Use it when the record specifies a persistent conjunctival condition limited to the right eye.
Clinical signs
Typical findings include ongoing redness, irritation, tearing, and mild discharge or foreign-body sensation. Clinical features vary; refer to documentation for laterality and whether the condition is chronic and simple.
When to use this code
Use this code when the provider documents simple chronic conjunctivitis affecting only the right eye. It is appropriate for outpatient or follow-up encounters where the diagnosis is confirmed and no more specific conjunctival disorder is documented.
Code it from the medical record, not from symptoms alone. If the note describes bilateral disease, acute conjunctivitis, or another specified subtype, choose the code that matches the documented condition.
Do not use for
Do not use this code for acute conjunctivitis, allergic conjunctivitis, or conjunctivitis not specified as chronic. Check documentation if the laterality is left, bilateral, or not stated.
Coding tip
Verify both chronicity and right-eye laterality in the provider note before assigning H10.421.