G438 – Colour vision detailed assessment - professional component
OHIP Diagnostic & Therapeutic Procedures Code — DIAGNOSTIC AND THERAPEUTIC PROCEDURES · Schedule of Benefits
Professional component of a colour vision detailed assessment. This service is payable only where underlying pathology is present or suspected and is not to be performed as a routine screening test. The full assessment requires the performance of one screening test (e.g., Ishihara, HRR, University) and at least two of the following detailed tests: - 100 Hue - D-15 - Lathony New Colour Test - Anomaloscope test This fee code covers the physician's interpretation and report for the test, which corresponds to the technical component G850. It cannot be claimed for screening tests like Ishihara, HRR, and University on their own.
When to Use
- Use G438 when evaluating patients with suspected optic nerve disease or toxic maculopathy where detailed colour discrimination quantification is clinically necessary.
- Apply this code when investigating acquired dyschromatopsia in patients with known retinal pathology, provided you have performed one screening test and two advanced tests like the D-15 or Anomaloscope.
Common Pitfalls
- Claiming G438 for routine colour vision screening in asymptomatic patients or for occupational/school requirements will trigger automatic audit rejections.
- Billing G438 without documenting the specific results of the two required advanced tests (e.g., 100 Hue, D-15) in the patient chart is a frequent cause of clawbacks.
- Submitting G438 without the corresponding technical component G850 often leads to payment delays or reconciliation errors.
Billing Tips
- Ensure your clinical notes explicitly state the suspected underlying pathology to justify the diagnostic necessity beyond basic screening.
- Always pair G438 with G850 to ensure both the professional interpretation and the technical performance of the assessment are captured.
Effective: April 1, 2025
J. Diagnostic and Therapeutic Procedures
DIAGNOSTIC AND THERAPEUTIC PROCEDURES
Diagnostic
Diagnostic and Therapeutic Procedures
The medical record must document that the assessment included one screening test and at least two of the following detailed tests: 100 Hue, D-15, Lathony New Colour Test, or anomaloscope test.
The record must indicate that the test was performed because underlying pathology is present or suspected.
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