R504 – Midtarsals
OHIP Radiology Code — MUSCULOSKELETAL SYSTEM SURGICAL PROCEDURES · Schedule of Benefits
This service is for an arthrotomy of the midtarsals. As a surgical procedure, it includes all associated common and specific elements as defined in the Schedule of Benefits. Payment is based on the role of the physician: Surgeon (suffix A), Assistant (suffix B), or Anaesthesiologist (suffix C). The assistant fee is calculated from 6 base units plus time units (), and the anaesthesiologist fee is calculated from 7 base units plus time units ().
When to Use
- Use R504 for an open arthrotomy of the midtarsal joints when the procedure is the primary focus of the surgical encounter.
- Use R504 for surgical exploration or drainage of the midtarsal joint space, distinguishing it from minor procedures like simple joint aspirations.
Common Pitfalls
- Billing R504 alongside other foot/ankle surgical codes without checking for Schedule of Benefits 'General Preamble' rules regarding multiple procedure discounting.
- Attempting to bill a second surgical assistant (suffix B) automatically; R504 is not on the pre-approved list and requires prior authorization from a medical consultant.
- Failing to document the Injury Severity Score (ISS) in the medical record when claiming the E420 trauma premium, which leads to automatic rejection or recovery during audit.
Billing Tips
- Ensure the surgical start time is accurately recorded, as the assistant (suffix B) and anaesthesiologist (suffix C) fees are time-dependent and rely on precise unit calculations.
- When performing R504 as an emergency procedure, verify the specific start time against E409/E410 or E400/E401 series to ensure the correct after-hours premium is applied to the appropriate suffix.
Effective: April 1, 2025
N. Musculoskeletal System Surgical Procedures
MUSCULOSKELETAL SYSTEM SURGICAL PROCEDURES
Surgical
Musculoskeletal System Surgical Procedures
Listed under Arthrotomy - Ankle.
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