G359 – Special single agent or multi-agent therapy
OHIP Diagnostic & Therapeutic Procedures Code — DIAGNOSTIC AND THERAPEUTIC PROCEDURES · Schedule of Benefits
Special single agent or multi-agent therapy – chemotherapy and/or biologic agent(s) with major toxicity that require frequent monitoring and prolonged administration periods and may require immediate intervention by the physician. General Chemotherapy Requirements: This service is for the pharmacologic therapy of malignancy or autoimmune disease, with administration supervised by a physician for intravenous infusion. The physician must be available to intervene in a timely fashion at the initiation and for the duration of the prescribed therapy to manage immediate and delayed toxicities. The fee for chemotherapy and patient assessment provided by a physician includes all patient assessments by any physician for a 24 hour period following treatment administration. [Commentary from Schedule] Examples of special agent therapy include: - high-dose methotrexate with folinic acid rescue - methotrexate given in a dose of greater than 1 g/m2 - high dose cisplatin greater than 75 mg/m2 given concurrently with hydration and osmotic diuresis - high dose cystosine, arabinoside (greater than 2 g/m2) - high dose cyclophosphamide (greater than 1 g/m2) - ifosfamide with MESNA protection - combination of biologic agents with complex chemotherapy.
When to Use
- Use G359 for high-dose chemotherapy regimens like methotrexate > 1 g/m2 or cisplatin > 75 mg/m2 that require active physician oversight for toxicity management.
- Use this code for complex multi-agent protocols involving the combination of monoclonal antibodies or cytokines with traditional chemotherapy agents.
- Select G359 when the clinical protocol necessitates immediate physician availability to manage acute infusion-related toxicities or complex hydration requirements.
Common Pitfalls
- Billing G359 alongside a standard office visit (A007) or consultation (A005) for the same patient on the same day is a violation of the 24-hour assessment rule.
- Submitting G359 for biologic agents that are not classified as monoclonal antibodies or cytokines will result in automatic rejection.
- Attempting to bill separate fees for venipuncture or vascular access line insertion is incorrect, as these are bundled into the G359 fee.
Billing Tips
- Ensure the infusion protocol explicitly documents the high-dose nature of the chemotherapy to justify the 'special' classification over standard G381 or G345 codes.
- Remember that the G359 fee covers all physician assessments for the 24-hour period post-administration, preventing additional claims for follow-up checks within that window.
Effective: April 1, 2025
J. Diagnostic and Therapeutic Procedures
DIAGNOSTIC AND THERAPEUTIC PROCEDURES
Procedure
Diagnostic and Therapeutic Procedures
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