Z318 – Trephine or endoscopic frontal sinusotomy
OHIP Psychiatric Code — RESPIRATORY SURGICAL PROCEDURES · Schedule of Benefits
Trephine or endoscopic frontal sinusotomy is an Independent Operative Procedure (IOP). Per the surgical preamble on page , if the major pre-operative visit was rendered in the 12 months prior to the IOP, only a minor assessment (A001) by a GP or a partial assessment by a specialist is payable on the same day. If the major pre-operative assessment is on the same day, no other assessment is payable. The fee includes associated pre- and post-operative care as defined for IOPs.
When to Use
- Use Z318 for an endoscopic frontal sinusotomy performed as a standalone procedure for chronic frontal sinusitis.
- Use Z318 for a frontal sinus trephine when external drainage is required for acute frontal sinusitis or mucocele management.
Common Pitfalls
- Billing an A001 or other assessment on the same day as the procedure is a common rejection; per SP4, no assessment is payable if the major pre-operative visit occurs on the same day as the IOP.
- Attempting to bill Z318 alongside other sinus procedures without applying the 85% reduction rule for secondary procedures, which is required for multiple IOPs performed by the same surgeon.
- Failure to recognize that Z318 is an IOP, meaning the fee is all-inclusive of routine post-operative care; billing additional follow-up visits within the global period will result in audit recovery.
Billing Tips
- If the major pre-operative assessment was performed within the 12 months prior to the procedure, you may bill an A001 on the day of the surgery, but ensure it is clearly linked to the pre-operative workup.
Effective: April 1, 2025
P. Respiratory Surgical Procedures
RESPIRATORY SURGICAL PROCEDURES
Surgical
Respiratory Surgical Procedures
As a 'Z' code, this service is an Independent Operative Procedure (IOP) and follows specific rules for pre-operative assessments as described on page .
The fee for this service includes pre- and post-operative care as outlined in the Surgical Preamble (, ).
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