Education and Prevention Committee Billing Briefs

Education and Prevention Committee (EPC) Billing Briefs are prepared jointly by the Ministry of Health (MOH) and the Ontario Medical Association (OMA) to provide general advice and guidance to physicians on billing matters.

Category: Anaesthesia, Critical Care, Emergency Medicine, Surgeons and Surgical Assistants 
Date of publication: November 3, 2022

Claims Tips: For claims payment purposes, the trauma premium and associated services must be submitted on the same claim record. The inclusion of medical records that support payment requirements with the submitted claim is always helpful to ensure accurate adjudication and prompt payment of complex procedures.

E420 is eligible for payment when payment rules are met

  • A trauma patient with an Injury Severity Score (ISS) listed on the medical record of:
    • >12 when the patient is less than 16 years of age
    • >15 when the patient is 16 years of age or older
  • The service is provided on the day of trauma, or within 24 hours of the trauma

Common claims Issues

  • Errors in calculation of ISS score
  • Claiming E420 > 24 hours following the trauma
  • Lack of documentation to support claim/assist in adjudication (example, date of trauma; ISS score; description of injuries that support ISS score calculation)

E420 applies to the following services when payment rules are met

  • Services listed in the following Sections of the Schedule of Benefits:
    • Consultations and Visits (Section A of the Schedule)
    • Obstetrics (Section K of the Schedule)
    • Surgical Procedures (Section M through Z of the Schedule)
  • Basic and time units provided by an anaesthesiologist or a surgical assistant.
  • The following resuscitative services: G391, G395, G521, G522, and G523.

E420 is not applicable to:

  • Any service, including diagnostic services, not listed above.
  • Other premium codes such as special visit premiums and after-hours premiums.

Payment information

The value of the premium is 50% of the fee payable for the eligible service(s) provided.

Calculation of an Injury Severity Score

The Injury Severity Score (ISS) is used to describe severity of injury in a trauma patient. Injuries are categorized in one of 6 body areas and scored according to the Abbreviated Injury Scale (AIS). The ISS score is the sum of the squares of the highest AIS score in each of three different areas. Table 1, Parts 1 and 2, provide examples of AIS scoring for a range of injuries.

While many online calculators include the ISS, these may lead to inaccurate calculations if accurate AIS scores are not used to generate ISS data. Definitive resources to inform AIS scoring, and ISS calculation are available on the Association for the Advancement of Automotive Medicine (AAAM) website.

Six body areas

  • Head or neck injuries include injury to the brain or cervical spine, skull or cervical spine fractures and asphyxia/suffocation.
  • Facial injuries include those involving mouth, ears, nose and facial bones.
  • Chest injuries include all lesions to internal organs, drowning and inhalation injury. Chest injuries also include those to the diaphragm, rib cage, and thoracic spine.
  • Abdominal or pelvic contents injuries include all lesions to internal organs. Lumbar spine lesions are included in the abdominal or pelvic region.
  • Extremities or pelvic girdle injuries include sprains, fractures, dislocations and amputations.
  • External and other trauma injuries include lacerations, contusions, abrasions, and burns, independent of their location on the body surface, except amputation burns that are assigned to the appropriate body region. Other traumatic events assigned to this ISS body region are electrical injury, frostbite, hypothermia and whole body (explosion-type) injury.
Table 1 - Part 1: Examples of the AIS Score
AIS ScoreHead/Neck (includes C-Spine)Face (includes Eye/Ear)Chest (includes T-Spine)
  1. Minor
  • Superficial scalp laceration
  • Corneal laceration
  • Tympanic membrane rupture
  • Zygoma fracture, non-comminuted
  • Tooth fracture
  • Abrasions/contusions/minor lacerations of thorax
  • Rib fracture – 1 rib
  • Cardiac contusion – minor
  • T-Spinous or transverse process fracture
  1. Moderate
  • Scalp laceration, >10cm + into subcutaneous tissue
  • Skull fracture, vault, closed
  • Epidural or subdural hematoma <0.6 cm
  • Subarachnoid hemorrhage, no LOC or LOC <=6 hours
  • Facial nerve laceration, unilateral
  • LeFort I or LeFort II fracture
  • Rib fractures – 2 ribs
  • Brachiocephalic vein – minor laceration
  • Lung contusion*, unilateral/minor
  • Sternal fracture
  • Pneumothorax
  • T-Vertebral compression >20% anterior height loss/burst
  1. Severe but not life-threatening
  • Total scalp loss
  • Skull fracture, vault, open with intact dura or depressed <= 2 cm
  • Subarachnoid hemorrhage, LOC >6 hours
  • Odontoid fracture
  • Facial nerve laceration, bilateral
  • LeFort III or panfacial fracture
  • Major laceration jugular vein; blood loss >20% by volume
  • External carotid artery, major transection; blood loss >20%
  • Lung contusion*, bilateral/minor or unilateral/major
  • Rib fractures >=3 ribs or with flail
  • Hemothorax
  1. Life-threatening but survival likely
  • Skull fracture, open with torn dura or depressed >2 cm
  • Epidural or subdural hematoma 0.6-1 cm thick, <=  30 cc
  • Incomplete spinal cord Injury
  • Facial fracture with blood loss >20% by volume
  • Cardiac contusion, major
  • Hemothorax, major blood loss >20% by volume
  • Major pneumothorax >50% collapse of lung
  • Open/sucking chest wound Diaphragm rupture with herniation
  • Lung contusion*, bilateral + major
  1. Critical with uncertain survival
  • Epidural or subdural hematoma >30 cc
  • Complete spinal cord injury
  • Tension pneumothorax
  • Bilateral flail chest
  • Major rupture thoracic aorta

* Lung contusion only applicable with imaging confirmation.

Table 1 - Part 2: Examples of AIS Score
AIS ScoreAbdominal/Pelvic Contents (includes L-Spine)Extremities/Pelvic GirdleExternal
  1. Minor
  • Abrasions/contusions/minor lacerations of abdominal wall
  • Superficial or minor abdominal penetrating injury
  • Abrasions/contusions/minor lacerations of extremities/pelvic girdle
  • Scalp laceration, superficial, superficial


  • Joint capsule rupture/tear
  • Carpal dislocation
  • First degree burn
  • 2nd degree burn <10%
  1. Moderate
  • Simple liver capsular tear, <= 3 cm parenchymal depth
  • Small or large bowel contusion or partial thickness injury
  • Minor kidney hematoma, subcapsular, nonexpanding
  • Chance fracture, lumbar spine, no neuro deficit
  • Most closed fractures and dislocations (some may = 1)
  • Median nerve laceration


    Pelvic ring fracture, isolated, stable, closed

  • 2nd or 3rd degree burn 10-19%
  • Degloving injury arm/forearm
  • Electrical injury
  1. Severe but
    not life-threatening
  • Liver laceration, >3 cm parenchymal depth
  • Small or large bowel perforation or full thickness laceration
  • Penetrating injury with blood loss >20%
  • Major kidney hematoma
  • Bladder rupture
  • Most open fractures
  • Complete brachial plexus injury


  • Below elbow or below knee amputations
  • Compartment syndrome with muscle loss
  • 2nd or 3rd degree burn 20-29%
  • Near drowning, without neurological deficit
  • Electrical injury with muscle necrosis
  1. Life-threatening but survival likely
  • Small or large bowel massive injury, large areas of devitalization, devascularization
  • Massive/complex bladder injury
  • Above elbow or above knee amputations
  • Femoral artery transection
  • Pelvic fracture, open or totally unstable or with moderate pelvic hematoma
  • 2nd or 3rd degree burn 30-39%
  • Near drowning, with neurological deficit
  1. Critical with uncertain survival
  • Renal hilum avulsion, Shattered kidneys
  • Transection abdominal aorta
  • Bilateral above knee amputations
  • Pelvic fracture with blood loss >20%
  • 2nd or 3rd degree burn 40-89%
  • Electrical injury with documented cardiac arrest

Reference: AAAM, The Abbreviated Injury Scale Dictionary, 2015 revision.


Example 1: Adult patient involved in a gas explosion presents with:
InjuryScoreBody areaHighest score/area (top 3)
Abrasions right hand1ExternalYes
Ruptured tympanic membrane1Head/neck 
Rib fracture, 5th, left1Chest 
Small bowel contusion2AbdomenYes
Femur fracture, left (open)3ExtremityYes
Tibial fracture, right (closed)2Extremity 

ISS = 12 + 22 + 32 = 14
This patient would not meet the criteria for the use of the E420 code. Note that only one of the scores associated with the femoral and tibial fractures may be counted in calculating the ISS as these both represent the extremity body area.

Example 2: Adult patient from motor vehicle-versus-pedestrian collision presents with:
InjuryScoreBody areaHighest score/area (top 3)
Epidural hematoma <0.6 cm thick2Head/neck 
LeFort III fracture3FaceYes
Rib fracture, 6/7/8, left side with flail3ChestYes
Small bowel contusion2Abdomen 
Tibial fracture, open3ExtremityYes

ISS = 32 + 32 + 32 = 27

This patient would meet the criteria for the use of the E420 code. Any applicable services provided on the same day as the trauma or within 24 hours of the injury would qualify for this premium. If two surgeons are required to provide surgical reconstruction of this patient’s injuries, both surgeons may claim primary surgical fee codes for the procedures that they perform components of.

The patient described above is admitted to the intensive care unit following initial emergency stabilization. 72 hours later, the patient is brought to the operating room for additional procedures related to the trauma. Is the E420 premium applicable at this stage?

No, the E420 trauma premium is only applicable within 24 hours of the initial trauma.

Example 3: Adult patient injured in workplace presents with:
InjuryScoreBody areaHighest score/area (top 3)
Above-elbow amputation4ExtremityYes

ISS = 42 = 16
This patient would meet the criteria for the use of the E420 code.

Example 4: Three-year-old child who fell from height:
InjuryScoreBody areaHighest score/area (top 3)
Thoracic vertebral fracture, >20% anterior compression, no neurological deficit3ChestYes
Rib fractures, 2 ribs2Chest 
Tibia fracture, closed2ExtremityYes

ISS = 32 + 22 = 13
This patient would meet the criteria for the use of the E420 code (>12 in patients <16 years of age).


Abbreviated Injury Scale; AIS; calculation of Injury Severity Score; E420; ISS; OHIP Claims, OHIP Payment second surgeon; trauma patients; Trauma premium

Contact information

For additional information, please visit the Resources for Physicians and the How to Get Help with Billing Questions pages on the ministry website.

If you have any billing or claims submission inquiries, please contact the Inquiry Services, Service Support Contact Centre (SSCC) by email or by calling 1-800-262-6524.

To provide feedback on EPC Billing Briefs, or to suggest topics for future EPC Billing Briefs, send an email to the attention of the joint MOH/OMA Education and Prevention Committee.

The Ministry of Health (MOH) and the Ontario Medical Association (OMA) have jointly prepared this educational resource to provide general advice and guidance to physicians on specific billing matters.

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Note: This document is technical in nature and is available in English only due to its limited targeted audience. This publication has been exempted from translation under the French Language Services Act. For questions or support regarding this document, please contact the Service Support Contact Centre (SSCC) by email or by calling 1-800-262-6524.

Remarque : Ce document est de nature technique et est disponible en anglais uniquement en raison de son public cible limité. Ce document a été exempté de la traduction en vertu de la Loi sur les services en français. Pour toute question ou de l’aide concernant ce document, veuillez contacter Les Services de renseignements, Centre de contact pour le soutien des services par courriel ou en téléphonant le 1-800-262-6524.