G435 – Tonometry
OHIP Diagnostic & Therapeutic Procedures Code — DIAGNOSTIC AND THERAPEUTIC PROCEDURES · Schedule of Benefits
Tonometry is the procedure for measuring the pressure inside the eyes (intraocular pressure). It is used to screen for glaucoma. Note: G435 may not be claimed in conjunction with an ophthalmological consultation or specific assessment as this is included in these services.
When to Use
- Use G435 when performing stand-alone intraocular pressure screening for a patient who is not undergoing a comprehensive ophthalmological assessment or consultation on the same day.
- Use this code for follow-up monitoring of intraocular pressure in patients with known ocular hypertension or glaucoma when the visit is limited strictly to this procedure and does not meet the criteria for an A001 or other assessment code.
Common Pitfalls
- Claiming G435 alongside an ophthalmological consultation (e.g., A015) or a general assessment (e.g., A001) will result in an automatic rejection, as tonometry is considered an inherent component of those services.
- Billing G435 for routine eye exams or refractive services is inappropriate, as these are generally non-insured services under OHIP.
Billing Tips
- If the tonometry is performed during an emergency visit, you may claim the appropriate Special Visit Premium in addition to G435, provided no other assessment code is billed for the same encounter.
Effective: April 1, 2025
J. Diagnostic and Therapeutic Procedures
DIAGNOSTIC AND THERAPEUTIC PROCEDURES
Procedure
Diagnostic and Therapeutic Procedures
G435 may not be claimed in conjunction with an ophthalmological consultation or specific assessment as this is included in these services.
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