G391 – Critical care - fourth and subsequent physicians
OHIP Diagnostic & Therapeutic Procedures Code — DIAGNOSTIC AND THERAPEUTIC PROCEDURES · Schedule of Benefits
G391 is a time-based service fee used in two distinct critical care scenarios: 1. Life Threatening Critical Care: This is for care rendered to a critically ill or injured patient with one or more vital organ systems acutely impaired, leading to a high probability of imminent life-threatening deterioration. G391 is payable per quarter-hour (or part thereof) for the fourth and subsequent physicians involved in the patient's care. The first three physicians use codes G521, G522, and G523. 2. Other Critical Care: This is for resuscitation assessment and procedures in an emergency where there is a potential threat to life or limb that, without intervention, would likely escalate to 'life-threatening critical care'. G391 is payable per quarter-hour (or part thereof) after the initial quarter-hour, which is billed using G395.
When to Use
- Use G391 for the fourth or subsequent physician providing life-threatening critical care when the first three physicians have already billed G521, G522, and G523.
- Use G391 for each additional 15-minute increment of 'other critical care' resuscitation after the initial 15 minutes billed under G395.
Common Pitfalls
- Billing G391 alongside G521, G522, or G523 is a common error; these codes are mutually exclusive for the same physician on the same day.
- Attempting to bill G391 for routine monitoring or standard procedures that are already considered included in the critical care fee, such as IV insertion or blood gas collection.
- Failing to document precise start and end times in the chart, which is mandatory for all time-based critical care codes.
Billing Tips
- Ensure that if total care exceeds two hours, the claim is submitted manually to avoid automated rejections for high time values.
- Verify that you are not billing G391 while simultaneously claiming a per diem fee for intensive care, ventilatory support, or comprehensive care, as these are restricted.
Effective: April 1, 2026
J. Diagnostic and Therapeutic Procedures
DIAGNOSTIC AND THERAPEUTIC PROCEDURES
Procedure
Diagnostic and Therapeutic Procedures
The time when the insured service started and ended must be recorded in the patient's permanent medical record or chart.
Examples of vital organ system failure include but are not limited to: central nervous system failure, circulatory failure, shock, renal, hepatic, metabolic and or respiratory failure.
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