ICD-10 Code H10.42 – Simple chronic conjunctivitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H10.42 – Simple chronic conjunctivitis
What it is
H10.42 identifies chronic conjunctivitis that is described as simple, meaning ongoing inflammation of the conjunctiva without a more specific subtype. Use this code when the record clearly documents simple chronic conjunctivitis.
Clinical signs
Typical findings include persistent conjunctival redness, irritation, tearing, and mild discharge or foreign-body sensation. Clinical features vary; refer to documentation.
When to use this code
Use H10.42 when the clinician documents simple chronic conjunctivitis and does not specify allergic, mucopurulent, or another more detailed form. It may apply to persistent eye irritation or inflammation recorded as chronic and simple. Check documentation if laterality or a different conjunctivitis type is noted.
Do not use for
Do not use this code for acute conjunctivitis, allergic conjunctivitis, or other named conjunctival disorders. If the chart specifies another cause or type, code that condition instead.
Coding tip
Match the code to the exact wording in the note; if “simple chronic conjunctivitis” is not stated, verify the diagnosis before assigning H10.42.