G457 – Professional component - limited procedure
OHIP Diagnostic & Therapeutic Procedures Code — DIAGNOSTIC AND THERAPEUTIC PROCEDURES · Schedule of Benefits
Professional component of a limited electromyography (EMG) and/or nerve conduction studies (NCS), as described in Schedule B. This is a limited procedure involving conduction studies on a single nerve (motor and/or sensory conduction) and/or limited EMG studies of the involved muscle(s) and/or a limited neuromuscular transmission study. The procedure must be performed using intramuscular placement of a recording needle electrode; claims for surface EMG or other EMG techniques are not eligible for payment. The nerve conduction study component involves direct electrical stimulation of the relevant peripheral nerve(s) with corresponding measurement(s) of evoked latency, conduction velocity, and amplitude using surface or percutaneous recording electrodes. Additional recordings, such as late responses or reflexes, are included in the service if rendered.
When to Use
- Use G457 when performing a limited EMG or NCS on a single nerve or muscle group, such as a focused study for carpal tunnel syndrome or a single-nerve entrapment.
- Use G457 when you are the physician providing the professional interpretation of a study performed by a technician, provided you also bill the technical component G466.
Common Pitfalls
- Billing G457 in conjunction with a consultation or assessment code (e.g., A007) is prohibited unless a separate, medically necessary consultation was explicitly requested by the referring provider.
- Attempting to bill G457 for surface EMG studies will result in rejection, as the code strictly requires intramuscular needle electrode placement per Schedule B requirements.
- Billing G457 on the same day as G473 is a hard rejection; ensure you are not attempting to claim both for the same patient on the same date of service.
Billing Tips
- If you own the equipment and supervise the technician, ensure you claim both G457 for the professional component and G466 for the technical component to capture the full value of the service.
Effective: April 1, 2026
J. Diagnostic and Therapeutic Procedures
DIAGNOSTIC AND THERAPEUTIC PROCEDURES
Diagnostic
Diagnostic and Therapeutic Procedures
A permanent record of the procedure must be maintained in the patient chart.
If a physician owns the EMG/NCS equipment and either employs and provides clinical supervision for a technician to perform the procedure or performs the procedure personally, then both the technical component (G466) and the professional component (G457) are payable to the physician.
Schedule B procedures refer to procedures performed using intramuscular placement of a recording needle electrode. Claims for surface EMG or other EMG techniques are not eligible for payment.
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