What are the billing rules for S321A?

Bill the repairs done during the trauma laparotomy as the add-ons listed under S321 (S34). E420 trauma premium applies when the Injury Severity Score is over 15 (age 16 or more) or over 12 (under 16), for services on the day of or within 24 hours of the trauma; the ISS must be in the record and the premium submitted on the same claim (GP109). When two surgeons perform components of the same procedure on such a trauma patient, each is paid the full surgical fee (SP3).

What is S321A often billed with?

E733, E734, E735, E736, E723 organ repair add-ons (S34). E420 trauma premium (GP109). E409/E410 after-hours premium (GP104).

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Billing code

S321A — Laparotomy - For Acute Trauma

Q: What is OHIP billing code S321A?

Laparotomy for acute trauma. Add-ons cover repair of intestine, spleen, liver, diaphragm, bladder or kidney during the same operation.

Trauma laparotomy

Bill S321 for a laparotomy for acute trauma, with listed add-ons for repairs of intestine, spleen, liver, diaphragm, bladder or kidney.

Watch for: Bill the repairs as the add-ons listed under S321, and record the Injury Severity Score to claim the E420 trauma premium.

Provider	Specialist	Assistant	Anaesthetist	Non-anaesthetist
$671.65	$0.00	$77.46	$95.76	$95.76

Code: S321A
Description: Laparotomy - For Acute Trauma
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

Laparotomy for acute trauma. Add-ons cover repair of intestine, spleen, liver, diaphragm, bladder or kidney during the same operation.

What it covers

S321 is laparotomy for acute trauma (S34).

Add-ons listed under it: E733 repair of intestine (single), E734 multiple and/or with resection, E735 splenectomy, E736 repair of lacerated liver, E739 repair of diaphragm, E723 repair of lacerated spleen, E693 repair of ruptured bladder and E694 nephrectomy (S34).

Billing rules

Bill the repairs done during the trauma laparotomy as the add-ons listed under S321 (S34).
E420 trauma premium applies when the Injury Severity Score is over 15 (age 16 or more) or over 12 (under 16), for services on the day of or within 24 hours of the trauma; the ISS must be in the record and the premium submitted on the same claim (GP109).
When two surgeons perform components of the same procedure on such a trauma patient, each is paid the full surgical fee (SP3).
Non-elective surgery in the evening, at night, on weekends or holidays takes E409 or E410 (GP104).
E676 morbid obesity premium may apply when BMI is over 40 and recorded (SP6, SP7).

Often billed with

E733, E734, E735, E736, E723 organ repair add-ons (S34).
E420 trauma premium (GP109).
E409/E410 after-hours premium (GP104).

Related codes: S312, E733, E734, E735, E736, E723, E739

Source: Schedule of Benefits (July 1, 2026), Digestive System Surgical Procedures, Abdomen, Peritoneum and Omentum, page S34.

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