N109 – Hemispherectomy
OHIP Otolaryngology Code — NEUROLOGICAL SURGICAL PROCEDURES · Schedule of Benefits
This code represents a hemispherectomy, a major cranial surgical procedure. The fee for the surgeon (suffix A) is a flat rate. The fees for a surgical assistant (suffix B) and an anaesthesiologist (suffix C) are calculated based on time and basic units. For N109, the basic units are 15 for the assistant and 15 for the anaesthetist. The calculation of time units and application of various premiums (e.g., after-hours, age-based) are governed by the rules in the General Preamble of the Schedule of Benefits.
When to Use
- Use N109 for the definitive surgical resection of a cerebral hemisphere in cases of intractable epilepsy or extensive hemispheric damage.
- Use this code for the primary surgeon's fee (suffix A) when performing a complete or functional hemispherectomy in a hospital setting.
Common Pitfalls
- Billing for a second assistant without prior written authorization from a medical consultant will result in an automatic rejection, as N109 is not on the pre-approved list.
- Attempting to stack E420 (Trauma Premium) with after-hours premiums (E409, E410, E400B, E401B, E400C, E401C) is prohibited and will trigger a claim adjustment.
- Failing to document the Injury Severity Score (ISS) in the medical record when claiming E420 will lead to a clawback during audit.
Billing Tips
- Ensure the age-based premium (AGE_PREMIUM_LT_16_YRS) is applied to both the surgeon (suffix A) and the assistant (suffix B) claims for patients under 16 years of age.
- When billing for the anaesthesiologist, remember to include applicable modifiers for patient status (e.g., E022C for high ASA) or procedural complexity (e.g., E002C for induced hypothermia) to supplement the base 15 units.
Effective: April 1, 2025
X. Neurological Surgical Procedures
NEUROLOGICAL SURGICAL PROCEDURES
Surgical
Neurological Surgical Procedures
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