C121 – Additional visits due to intercurrent illness
OHIP Surgical Procedures Code — CONSULTATIONS AND VISITS · Schedule of Benefits
As per , after 5 weeks of hospitalization, any assessment in hospital required as a result of an acute intercurrent illness in excess of the weekly or monthly limits for subsequent visits constitutes C121. The weekly or monthly limits for subsequent visits do not apply to additional visits due to intercurrent illness.
When to Use
- Use C121 when a patient has exceeded the weekly or monthly subsequent visit limits due to a new, distinct acute illness (e.g., hospital-acquired pneumonia or acute delirium) occurring after the 5-week threshold.
- Use C121 for additional assessments required by a change in clinical status that necessitates a level of care beyond the standard subsequent visit frequency allowed under the Schedule of Benefits.
Common Pitfalls
- Billing C121 for routine follow-up of the primary reason for admission, which does not constitute an acute intercurrent illness and will be rejected or clawed back during audit.
- Failing to document the specific intercurrent illness; simply noting 'patient seen' is insufficient to justify the override of standard visit frequency limits.
- Attempting to bill C121 before the 5-week hospitalization threshold has been met, as standard subsequent visit codes must be used until that time.
Billing Tips
- Always append the E083 or E084 premium to C121 to maximize the value of the assessment, provided you meet the MRP eligibility criteria.
- Ensure your clinical notes explicitly differentiate the intercurrent illness from the patient's baseline chronic condition to support the medical necessity of the additional visit.
Effective: April 1, 2026
A. Consultations and Visits
CONSULTATIONS AND VISITS
Assessment
Hospital and Institutional Consultations and Assessments
The medical record must document the acute intercurrent illness that necessitated the additional visit, establishing medical necessity.
See in the General Preamble for payment rules.
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