R431 – Baker's cyst - simple
OHIP Radiology Code — MUSCULOSKELETAL SYSTEM SURGICAL PROCEDURES · Schedule of Benefits
Simple excision of a Baker's cyst, a fluid-filled sac behind the knee. As a surgical procedure, the fee includes the pre-operative assessment (if it's the 'major pre-operative visit'), the operation itself, and normal post-operative care.
When to Use
- Use R431 for the definitive surgical excision of a symptomatic Baker's cyst when non-operative management has failed.
- Select R431 when the procedure is performed as a standalone excision, distinguishing it from more complex synovectomy procedures like R429.
Common Pitfalls
- Billing a separate office assessment (A007) on the same day as the R431 procedure will result in a rejection, as the pre-operative assessment is included in the surgical fee.
- Attempting to bill R431 alongside R429 for the same knee is considered unbundling and will trigger a claim rejection for duplicate or overlapping services.
Billing Tips
- Always ensure the surgical report clearly describes the excision of the cyst to justify the R431 fee versus a simple aspiration, which would be billed as a minor procedure.
Effective: April 1, 2025
N. Musculoskeletal System Surgical Procedures
MUSCULOSKELETAL SYSTEM SURGICAL PROCEDURES
Surgical
Musculoskeletal System Surgical Procedures
The medical record must establish that an insured service was provided, the service for which the account is submitted is the service that was rendered, and the service was medically necessary.
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