What is OHIP billing code X400?

X400 is "CT head - without IV contrast", an OHIP Laboratory code from the Ontario Schedule of Benefits (Physician Services).

How much does X400 pay?

The current OHIP fee for X400 is $0.00, effective 2025-04-01, per the Ontario Schedule of Benefits.

How do I bill X400 to OHIP?

X400 is submitted through OHIP's MCEDT claims system, either directly or via billing software. SnapBill validates X400 claims against the Schedule of Benefits rules before submission.

What codes are related to X400?

Codes related to X400 in the Schedule of Benefits include X401, X188, E874, X402, X405, X408.

All codes

X400

X400 – CT head - without IV contrast

OHIP Laboratory Code — DIAGNOSTIC RADIOLOGY · Schedule of Benefits

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Represents the professional and technical components for a Computed Tomography (CT) scan of the head, performed without the administration of intravenous contrast material.

When to Use

Use X400 for routine non-contrast head CT scans to rule out acute intracranial hemorrhage or mass effect in emergency or inpatient settings.
Use X400 as the base code when performing a CT perfusion study (E874) for acute stroke investigation where contrast is administered solely for the perfusion component, not for a diagnostic contrast-enhanced head CT.
Use X400 for follow-up imaging of known intracranial pathology where contrast enhancement is not clinically indicated.

Common Pitfalls

Billing X400 concurrently with X401 or X188 for the same patient encounter will trigger an automatic rejection as these are mutually exclusive.
Failing to document medical necessity for the specific scan type can lead to audit recovery, especially if the clinical indication suggests contrast was required but not performed.
Attempting to bill E874 as a standalone code without an associated base code like X400 will result in a rejection.

Billing Tips

When performing an acute stroke protocol, ensure you pair X400 with E874 rather than using a contrast-enhanced code like X401 to avoid billing errors.
If interpreting via PACS for an acute care patient after hours, append the appropriate E-series premium (E406, E407, or E408) to X400 to maximize reimbursement for urgent interpretation.

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Provider Fee$0.00

Non-Anaesthetist Fee$43.25

Effective: April 1, 2025

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