G858 – Visual fields - static - technical component
OHIP Diagnostic & Therapeutic Procedures Code — DIAGNOSTIC AND THERAPEUTIC PROCEDURES · Schedule of Benefits
This code represents the technical component for static visual fields perimetry. It is only eligible for payment when underlying pathology is present or suspected. The service requires: - A permanent record with measurement of a minimum of 50 points per eye. - Quantification of deficient points. - Monitoring of fixation/reliability. The corresponding professional component is billed using G432.
When to Use
- Use G858 when performing static perimetry to monitor progression of glaucoma or suspected optic nerve pathology where at least 50 points are measured per eye.
- Use this code for the technical component of visual field testing in patients with neurological deficits or suspected chiasmal lesions requiring precise quantification of scotomas.
Common Pitfalls
- Billing G858 for routine screening or refractive exams will trigger an audit, as the code strictly requires documented underlying pathology.
- Submitting G858 without the corresponding professional interpretation code G432 often leads to claims being flagged for incomplete diagnostic service reporting.
- Failure to maintain a permanent record demonstrating at least 50 points per eye and fixation reliability indices will result in full recovery of the fee during a post-payment audit.
Billing Tips
- Ensure the technical component is billed at 86.10% of the fee if the service is performed within a hospital setting to avoid automatic rejection or adjustment.
- Always link the technical component G858 to the professional component G432 on the same date of service to ensure the diagnostic episode is considered complete by the MOH.
Effective: April 1, 2026
J. Diagnostic and Therapeutic Procedures
DIAGNOSTIC AND THERAPEUTIC PROCEDURES
Diagnostic
Diagnostic and Therapeutic Procedures
Permanent record with measurement of a minimum of 50 points per eye.
Quantification of deficient points.
Monitoring of fixation/reliability.
The physician submitting a claim for the technical component is responsible for the complete quality assurance process for all elements of the technical component of the service, including data acquisition, reporting, and record keeping. The physician must be able to demonstrate the above upon request by the MOH.
Visual fields static perimetry, is only eligible for payment where underlying pathology is present or suspected and the following services are rendered: permanent record with measurement of a minimum of 50 points per eye, quantification of deficient points and monitoring of fixation/reliability.
Ready to bill this code?
SnapBill makes OHIP billing simple — auto-filled codes, validation, and batch submission.