G820 – OCT unilateral or bilateral - glaucoma
OHIP Diagnostic & Therapeutic Procedures Code — DIAGNOSTIC AND THERAPEUTIC PROCEDURES · Schedule of Benefits
Optical coherence tomography (OCT) for glaucoma, performed unilaterally or bilaterally. The service is payable when the physician interprets the results and either performs the procedure or supervises its performance. It is insured only for the diagnosis and management of glaucoma when the ophthalmologist is the most responsible physician for the patient's care. This service is not payable for patients younger than 18 years of age or when rendered for preparation related to cataract surgery.
When to Use
- Use G820 for routine monitoring of structural nerve fiber layer thinning in patients with an established diagnosis of glaucoma.
- Use G820 when investigating a patient with elevated intraocular pressure or suspicious optic nerve head appearance to confirm a glaucoma diagnosis.
Common Pitfalls
- Billing G820 for OCT scans performed as part of pre-operative assessment for cataract surgery, which is explicitly excluded from coverage.
- Exceeding the annual limit of four services when combining G818, G820, and G821, leading to automatic claim rejections.
- Attempting to bill G820 for patients under 18 years of age, for whom G823 is the appropriate code.
Billing Tips
- Ensure your clinical notes explicitly document the glaucoma-related indication, as G820 is strictly restricted to the management of glaucoma and not general retinal pathology (which falls under G818 or G821).
Effective: April 1, 2025
J. Diagnostic and Therapeutic Procedures
DIAGNOSTIC AND THERAPEUTIC PROCEDURES
Diagnostic
Diagnostic and Therapeutic Procedures
Payable for patients 18 years of age and older.
Except as described in payment rule #2, OCT is an insured service only: a. for the diagnosis and management of retinal disease and/or glaucoma; and b. when the ophthalmologist performing the service is the physician most responsible for the care of the patient's retinal disease and/or glaucoma.
Any OCT service rendered in whole or in part for preparation related to cataract surgery is not eligible for payment.
G818, G820, G821 and G822 are not eligible for payment when rendered on a patient younger than 18 years of age.
G822 is only eligible for payment when the limit of any combination of G818, G820 or G821 is reached.
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