What are the billing rules for G523A?

Time is physician time fully devoted to the patient at the bedside, in the ED or on the floor where the patient is; it excludes separately billable procedures and may be consecutive or not (J26). You can't care for other patients during the time claimed (J26). Payable per physician per patient to the first three physicians; the fourth and later physicians bill G391 (J26).

What is G523A often billed with?

G521 first ¼ hour (J26). G522 each ¼ hour after the first ½ hour (J26). E420 trauma premium (GP109).

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Billing code

G523A — Life Threatening emergency situation - 2nd 1/4 hour

Q: What is OHIP billing code G523A?

Life-threatening critical care: the second quarter-hour (or part) of physician time with a critically ill or injured patient.

Critical care, second 15 minutes

Bill G523 for the second quarter hour of bedside life-threatening critical care, after G521.

Watch for: Record start and stop times in the chart or it isn't payable; only the first three physicians can bill it.

Provider	Specialist	Assistant	Anaesthetist	Non-anaesthetist
$64.50	$0.00	$0.00	$0.00	$0.00

Code: G523A
Description: Life Threatening emergency situation - 2nd 1/4 hour
FHO+ basket: Not in the FHO+ base rate basket (Schedule 2 or 2B).
Effective date: Apr 1, 2026
Termination date: No end date

Explanation

Updated October 26, 2026

Life-threatening critical care: the second quarter-hour (or part) of physician time with a critically ill or injured patient.

What it covers

Life-threatening critical care is care of a critically ill or injured patient whose illness or injury acutely impairs one or more vital organ systems, causing failure, so that imminent life-threatening deterioration is highly probable (J26).

G521 pays the first ¼ hour, G523 the second ¼ hour, and G522 each ¼ hour after the first ½ hour (J26).

Billing rules

Time is physician time fully devoted to the patient at the bedside, in the ED or on the floor where the patient is; it excludes separately billable procedures and may be consecutive or not (J26).
You can't care for other patients during the time claimed (J26).
Payable per physician per patient to the first three physicians; the fourth and later physicians bill G391 (J26).
Not payable separately the same day by the same physician: assessment and monitoring, IV lines, cutdowns, arterial/venous catheters, CVP lines, intubation, tracheal toilet, blood gases, NG tubes, urinary catheters, pressure infusion sets and drugs, defibrillation and cardioversion (J26).
Not payable the same day you are paid a Critical Care, Ventilatory Support, Comprehensive Care or Neonatal Intensive Care per diem; not with A384 or K181 (J27).
Record start and stop times in the chart, or it is not payable (J27).
E420 trauma premium applies for qualifying trauma patients (ISS over 15, or over 12 under age 16) within 24 hours of the trauma (GP109).

Often billed with

G521 first ¼ hour (J26).
G522 each ¼ hour after the first ½ hour (J26).
E420 trauma premium (GP109).

Related codes: G521, G522, G391, G395, E420, G400

Source: Schedule of Benefits (July 1, 2026), Diagnostic and Therapeutic Procedures, Critical Care, page J26.

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