G040 – Drugs of abuse screen, urine
OHIP Diagnostic & Therapeutic Procedures Code — DIAGNOSTIC AND THERAPEUTIC PROCEDURES · Schedule of Benefits
Drugs of abuse screen, urine, must include testing for at least four drugs of abuse per test.
When to Use
- Use G040 when performing a routine urine drug screen for a patient in an opioid agonist treatment program where at least four specific drug classes are tested.
- Use G040 for monitoring compliance in chronic pain patients when the laboratory test panel meets the minimum four-drug requirement and you hold the required Section 56 exemption.
Common Pitfalls
- Billing G040 without a corresponding K623, K624, or a direct physical encounter service (consultation or assessment) in the same month will result in automatic rejection.
- Exceeding the monthly frequency limits (3 or 5 services depending on K682/K683 billing) will trigger claim rejections, as these limits are tracked across all physicians for that patient.
- Attempting to bill G040 alongside G041, G042, or G043 for the same urine sample is a billing error, as only one code is payable per specimen.
Billing Tips
- Ensure your clinical documentation explicitly lists the four drugs tested to support the G040 claim in the event of an audit, as the code requires a minimum of four drug classes.
- Verify that you have an active Section 56 exemption on file, as this is a mandatory prerequisite for payment of G040 in the context of opioid agonist maintenance treatment.
Effective: June 1, 2025
J. Diagnostic and Therapeutic Procedures
DIAGNOSTIC AND THERAPEUTIC PROCEDURES
Laboratory
Diagnostic and Therapeutic Procedures
As with all insured services, documentation must establish that an insured service was provided, the service claimed is the service that was rendered, and the service was medically necessary.
Payment rules:
1. For the purposes of opioid agonist maintenance treatment, G040, G042, G041 and G043 are only eligible for payment to a physician who has an active general exemption for methadone maintenance treatment or chronic pain treatment with methadone pursuant to Section 56 of the Controlled Drugs and Substances Act 1996.
2. G040 and G041 are limited to a maximum of five (5) services per patient (any combination) per month to any physician when K682 or K683 is payable.
3. G042 and G043 are limited to a maximum of four (4) services per patient (any combination) per month to any physician when K682 or K683 is payable.
4. Any combination of G040, G041, G042 and G043 is limited to a maximum of three (3) services per patient per month for management of a patient with chronic pain, an addiction, or receiving opioid agonist treatment program where K682 or K683 is not payable in the month for the same patient to any physician.
5. G040, G041, G042 and G043 are not eligible for payment unless K623 or K624 or a consultation, assessment or time-based service involving a direct physical encounter with the patient is payable in the same month to the same physician rendering the G040, G041, G042 or G043 service.
8. Only one of G040, G041, G042 or G043 is eligible for payment per urine sample.
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