M400B – Surgical assistant service (authorization required)
OHIP Ophthalmology Code — GENERAL PREAMBLE · Schedule of Benefits
M400B is a billing code used for surgical assistant services when the Schedule of Benefits does not list a specific basic unit value under the 'Asst' column for a procedure, but does list one under the 'Anae' column. In this case, the number of basic units for the assistant's service is taken from the 'Anae' column. This service is only eligible for payment upon authorization by a medical consultant, which requires the submission of a letter from the surgeon explaining why an assistant was necessary. The total fee is calculated by adding these basic units to the applicable time units and multiplying the sum by the standard assistant unit fee.
When to Use
- Use M400B when the Schedule of Benefits lists an 'Anae' unit value for a procedure but lacks a specific 'Asst' unit value, requiring you to borrow the anaesthesia units for the assistant fee.
- Use this code for complex surgical cases where the surgeon provides a formal letter justifying the necessity of an assistant for a procedure that does not explicitly list assistant units.
Common Pitfalls
- Submitting M400B without the mandatory surgeon's letter of justification will result in an automatic rejection; ensure the letter is attached to the claim submission.
- Failing to use the 'Anae' column units as the basis for the calculation is a common error; do not default to arbitrary unit values when the Schedule provides a specific reference column.
Billing Tips
- When calculating the total fee, ensure you sum the 'Anae' basic units and the applicable time units (per Appendix H) before applying the standard assistant unit fee multiplier.
- Always verify if the procedure qualifies for age-based premiums, as these apply to the total of both basic and time units calculated via M400B.
No fee information available.
GP. General Preamble
GENERAL PREAMBLE
Procedure
Surgical Assistants' Services
Authorization by a medical consultant is required.
A letter from the surgeon outlining the reason the assistant was required must be submitted with the claim.
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