iStent Surgery – Billing & Coding

iStent is a minimally invasive glaucoma surgery (MIGS) procedure.

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🔹 What is iStent?

A tiny implant that:

• Improves fluid drainage
• Reduces intraocular pressure

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🔹 CPT Codes

• 0191T – iStent insertion (initial)
• 0376T – Each additional stent

👉 These are Category III codes (temporary/tracking codes)

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🔹 When Performed

Often combined with:

• Cataract surgery (66984)

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🔹 Billing Considerations

• Some payers consider it investigational
• Documentation must support:
  • Glaucoma diagnosis
  • Medical necessity

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🔹 Common Denials

• Non-covered procedure

Missing documentation