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N159
N159 – Craniotomy plus evacuation - infratentorial
OHIP Otolaryngology Code — NEUROLOGICAL SURGICAL PROCEDURES · Schedule of Benefits
A craniotomy with evacuation for an infratentorial intracranial cyst. Per , this service includes interventriculostomy when performed.
When to Use
- Use N159 for the surgical evacuation of an infratentorial intracranial cyst, such as a cerebellar or posterior fossa cyst.
- Use N159 when a craniotomy is performed specifically for the drainage of an infratentorial lesion, as it explicitly includes the work of an interventriculostomy if required during the same procedure.
Common Pitfalls
- Do not bill an interventriculostomy separately; the Schedule of Benefits explicitly states that N159 includes this service, and separate billing will result in a rejection or recovery.
- Avoid using N159 for supratentorial procedures; ensure the operative report clearly defines the infratentorial location to prevent audit adjustments to lower-valued codes.
- Failure to document the Injury Severity Score (ISS) when attempting to claim the E420 trauma premium on top of N159 is a frequent cause of claim rejection.
Billing Tips
- When performing multiple procedures during the same anesthetic, ensure N159 is designated as the major procedure to correctly calculate the base units for the surgical assistant (N159B) and anaesthetist (N159C).
Provider Fee$1,065.05
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
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