C721 – Complex medical specific re-assessment - Occupational Medicine
OHIP Surgical Procedures Code · Schedule of Benefits
A re-assessment of a patient because of the complexity, obscurity, or seriousness of the patient’s condition. This service is rendered by a specialist in Occupational Medicine for a hospital in-patient and requires a full, relevant history and physical examination of one or more systems.
When to Use
- Use C721 for a complex, in-patient re-assessment of an occupational injury or illness when the patient's condition requires a detailed, multi-system physical examination.
- Apply this code when the clinical complexity of the occupational condition necessitates a formal written report to the primary care physician, distinguishing it from a standard C722 subsequent visit.
Common Pitfalls
- Failure to generate and send a formal written report to the primary care physician will trigger an automatic audit adjustment to a lower-valued assessment code.
- Exceeding the 4-service limit per 12-month period (shared with C723) will result in a payment reduction to the lesser assessment fee rate.
- Billing C721 on the same day as a C722 subsequent visit for the same patient will result in a rejection, as the assessment is intended to encompass the daily clinical review.
Billing Tips
- Ensure the chart documentation explicitly reflects the 'complexity, obscurity, or seriousness' of the condition to justify the C721 fee over the standard C722 subsequent visit.
- If performing the service via virtual care, append the 'A' suffix and confirm the encounter was conducted via video, as telephone-only encounters are ineligible for this specific code.
Effective: April 1, 2026
Non-Emergency Hospital In-Patient Services
Assessment
If the usage limit of 4 per 12 months is exceeded, the fee will be adjusted to a lesser assessment fee.
C721 is the in-patient equivalent of A721.
Admission assessments constitute a re-assessment (like C721) if the admitting physician has previously assessed the patient for the same illness within 90 days.
Ready to bill this code?
SnapBill makes OHIP billing simple — auto-filled codes, validation, and batch submission.