ICD-10 Code H00.01 – Hordeolum externum (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H00.01 – Hordeolum externum
What it is
Hordeolum externum is an acute, localized infection of an eyelid gland at the lash line. It is commonly called an external stye and affects the outer eyelid tissues.
Clinical signs
Typical findings include a painful, red, swollen bump on the eyelid margin, often with tenderness and localized drainage. Clinical features vary; refer to documentation.
When to use this code
Use this code when the record documents an external stye or infection limited to the eyelid margin. It is appropriate when the provider identifies hordeolum externum by exam or assessment. If the note only says “eyelid swelling” or “eye irritation,” check documentation before coding.
Do not use for
Do not use this code for internal hordeolum, chalazion, or nonspecific conjunctival disease. If the diagnosis is unclear or another eyelid disorder is documented, check documentation.
Coding tip
Code the documented eyelid location carefully, because external and internal hordeola are different codes.