All codes
N158
N158 – Craniotomy plus evacuation - supratentorial
OHIP Otolaryngology Code — NEUROLOGICAL SURGICAL PROCEDURES · Schedule of Benefits
A surgical procedure that involves performing a craniotomy to evacuate a supratentorial intracranial cyst. The service includes an interventriculostomy as noted on page :. This procedure is eligible for surgical assistant and anaesthesia services. The fee for a surgical assistant (suffix B) is based on 15 basic units plus time units. The fee for an anaesthesiologist (suffix C) is based on 15 basic units plus time units.
When to Use
- Use N158 for the surgical evacuation of a supratentorial intracranial cyst when the procedure includes an interventriculostomy.
- Select N158 for non-elective supratentorial cyst evacuations occurring after hours, ensuring the appropriate E409A or E410A premium is applied.
Common Pitfalls
- Do not bill an additional code for interventriculostomy, as it is explicitly included in the N158 fee and will result in a rejection or recovery.
- Do not assume a second surgical assistant is automatically payable; N158 is not on the pre-approved list and requires a formal letter of justification to a medical consultant.
- Failure to document the Injury Severity Score (ISS) in the medical record will result in the rejection of the E420 trauma premium.
Billing Tips
- Ensure the procedure start time is accurately recorded, as the 50% (E409A) or 75% (E410A) non-elective premiums are strictly dependent on the commencement time.
- When billing for pediatric patients, verify the exact age in days or years to apply the correct age-based premium (e.g., AGE_PREMIUM_LT_30D vs AGE_PREMIUM_LT_1Y) to maximize the procedural fee.
Provider Fee$968.50
Surgical Assistant Fee$187.65
Anaesthetist Fee$232.35
Non-Anaesthetist Fee$232.35
Effective: April 1, 2025
Category
X. Neurological Surgical Procedures
Subcategory
NEUROLOGICAL SURGICAL PROCEDURES
Service Type
Surgical
Code Classes
Neurological Surgical Procedures
Ready to bill this code?
SnapBill makes OHIP billing simple — auto-filled codes, validation, and batch submission.