E401C – Nights anaesthetic premium
OHIP Surgical Assists Code — ANAESTHESIOLOGISTS’ SERVICES · Schedule of Benefits
E401C is an after-hours premium for anaesthesiologists' services. It provides a 75% increase to the total anaesthetic fee for cases that commence during the night, defined as the period from 00:00h to 07:00h. The total anaesthetic fee is calculated by adding the basic units and time units for the procedure as defined in the Schedule of Benefits on page . This premium can be billed in addition to applicable anaesthesia special visit premiums such as C998C, C985C, or C999C.
When to Use
- Use E401C when an anaesthetic procedure commences between 00:00h and 07:00h to apply a 75% increase to the total anaesthetic fee.
- Apply E401C in conjunction with C999C when you are called into the hospital for an emergency case during the night shift.
Common Pitfalls
- Billing E401C for cases starting at 07:00h or later, which falls outside the defined night window and will result in a rejection.
- Failing to include the base anaesthetic units and time units in the calculation, as E401C is a percentage-based premium that requires a valid base fee to trigger.
- Confusing E401C with E400C; ensure the start time is strictly within the 00:00h to 07:00h window to avoid audit discrepancies.
Billing Tips
- Always pair E401C with the appropriate special visit premium like C999C to maximize reimbursement for emergency travel during night hours.
- Ensure the start time of the anaesthetic is clearly documented in the record, as this is the primary audit point for verifying the 75% premium eligibility.
Percentage Premium: 0.75%
This code applies a percentage increase to the base procedure fee
Effective: January 23, 2026
GP. General Preamble
ANAESTHESIOLOGISTS’ SERVICES
PercentageIncrease
Anaesthesiologists' Services, Other Premiums (including After Hours Procedure Premiums)
These premiums are payable when a case commences: E401C: Nights (00:00h – 07:00h) - increase the total anaesthetic fee by 75%
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