G499 – Intravenous tolbutamide test
OHIP Diagnostic & Therapeutic Procedures Code — DIAGNOSTIC AND THERAPEUTIC PROCEDURES · Schedule of Benefits
An intravenous tolbutamide test. This procedure is listed in the Diagnostic and Therapeutic Procedures section of the Schedule, under Endocrinology and Metabolism.
When to Use
- Use G499 specifically for the administration and monitoring of an intravenous tolbutamide test performed for diagnostic purposes in an endocrine investigation.
- Select G499 when the procedure is performed in a hospital or clinical setting where the physician is actively managing the infusion and monitoring the patient's response.
Common Pitfalls
- Do not attempt to bill G499 with E409 or E410, as this procedure is not classified as a Major Invasive Procedure and is ineligible for these specific after-hours premiums.
- Avoid applying age-based fee premiums to G499, as the Schedule explicitly excludes this code from age-related modifiers per GP64.
Billing Tips
- Ensure the clinical documentation clearly supports the diagnostic necessity of the tolbutamide test to withstand potential audit scrutiny regarding the procedure's specific indication.
Effective: April 1, 2025
J. Diagnostic and Therapeutic Procedures
DIAGNOSTIC AND THERAPEUTIC PROCEDURES
Diagnostic
Diagnostic and Therapeutic Procedures
The clinical decision(s) formulated by the physician or substitute physician may be communicated to the patient, patient's relative, patient's representative or other caregiver by a staff member other than the physician.
Month refers to a calendar month.
If G514 and G520 are claimed in the same month by the same physician for the same patient, the total fee eligible for payment will be adjusted to the value of G520.
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