C661 – Complex Medical Specific Re-Assessment
OHIP Surgical Procedures Code — Paediatrics (26) · Schedule of Benefits
A complex medical specific re-assessment is a re-assessment of a patient because of the complexity, obscurity, or seriousness of the patient's condition and includes all the requirements of a medical specific re-assessment. The physician must report his/her findings, opinions, or recommendations in writing to the patient's primary care physician or the amount payable for the service will be adjusted to a lesser assessment fee. As a 'C' prefix code, this service is for non-emergency hospital in-patients. This code is listed under the Paediatrics (<specialtyCode>26</specialtyCode>) specialty section. Refer to and for general rules on assessments and in-patient services.
When to Use
- Use C661 for a non-emergency hospital in-patient requiring a detailed re-evaluation of a multi-system or obscure paediatric condition that exceeds the scope of a standard C263 re-assessment.
- Apply this code when the clinical complexity necessitates a formal written report to the referring primary care physician to ensure continuity of care for a serious, ongoing condition.
Common Pitfalls
- Failure to generate and send a formal written report to the primary care physician will trigger an automatic downward adjustment to a lower-valued assessment fee.
- Exceeding the limit of 4 combined medical specific assessments and complex re-assessments per patient per physician per 12-month period will result in automatic payment reductions.
- Billing C661 for routine in-patient follow-ups that lack the documented complexity or obscurity required by the Schedule of Benefits will lead to audit recovery.
Billing Tips
- Ensure the written report to the primary care physician is dated and filed, as this is the primary documentation requirement to maintain the full fee value.
- If the patient is in an ICU or CCU, remember to append the C101 premium to the C661 claim to maximize the encounter value.
Effective: June 1, 2025
Consultations and Visits
Paediatrics (26)
Assessment
Hospital and Institutional Consultations and Assessments, Assessments
The physician must report his/her findings, opinions, or recommendations in writing to the patient's primary care physician or the amount payable for the service will be adjusted to a lesser assessment fee.
The medical record must contain a record of the service that establishes that the service was provided, is the service for which the account is submitted, and was medically necessary.
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