ICD-10 Code B30 – Viral conjunctivitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B30 – Viral conjunctivitis
What it is
B30 identifies viral conjunctivitis, an inflammation of the conjunctiva caused by a viral infection. Use it when the record clearly states viral cause rather than bacterial, allergic, or unspecified conjunctivitis.
Clinical signs
Typical findings include red eye, watery discharge, irritation, and conjunctival swelling. Clinical features vary; refer to documentation, especially when the note distinguishes viral conjunctivitis from other eye infections.
When to use this code
Use B30 when the provider documents viral conjunctivitis as the diagnosis or confirms a viral etiology. It is appropriate for encounters focused on evaluation, follow-up, or management of this specific infection. Check documentation if the note only says “conjunctivitis” without cause.
Do not use for
Do not use B30 for bacterial, allergic, or unspecified conjunctivitis. If the chart does not identify a viral cause, choose the more accurate documented diagnosis or check documentation.
Coding tip
Confirm the provider’s documented etiology and laterality details, if present, before assigning B30.