C483 – Medical specific assessment
OHIP Surgical Procedures Code — CONSULTATIONS AND VISITS · Schedule of Benefits
A medical specific assessment is a service rendered by a specialist for a non-emergency hospital in-patient. It requires a full history of the presenting complaint and a detailed examination of the affected part(s), region(s), or system(s) necessary to formulate a diagnosis, rule out other diseases, and/or evaluate function. The 'C' prefix indicates the service is for non-emergency in-patient services in an acute care hospital.
When to Use
- Use C483 for a non-emergency, detailed in-patient assessment when a full history and physical exam are required to formulate a diagnosis for a new or distinct clinical problem.
- Use C483 for a hospital admission assessment if the patient has not been seen by you for the same illness within the previous 90 days.
Common Pitfalls
- Billing C483 when a consultation (C485) is more appropriate; if you are providing a formal opinion requested by another physician, C485 is the correct code.
- Exceeding the 4-per-year limit for combined specific assessments, which triggers an automatic adjustment to a lower-valued assessment fee.
- Billing C483 for an admission assessment when you have already assessed the patient for the same condition within the last 90 days, which should be billed as a re-assessment (C484).
Billing Tips
- If you are seeing a trauma patient within 24 hours of injury and meet the ISS requirements, ensure you append the E420 premium to the C483 claim to receive the 50% increase.
- Always verify the 90-day window before billing C483 for an admission; if the patient was seen in your office for the same issue shortly before admission, C483 will be rejected or adjusted.
Effective: June 1, 2025
A. Consultations and Visits
CONSULTATIONS AND VISITS
Assessment
Hospital and Institutional Consultations and Assessments, Assessments
A full history of the presenting complaint.
A detailed examination of the affected part(s), region(s), or system(s) needed to make a diagnosis, and/or exclude disease, and/or assess function.
See General Preamble to for rules regarding non-emergency hospital in-patient services.
For emergency calls and other special visits to in-patients, use General Listings and Premiums when applicable - see General Preamble to .
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