Error code
L1 — Service already paid to another lab
Paid to another lab
OHIP already paid another laboratory for this service for the patient, so it isn't paid twice.
What to do: Check whether another laboratory performed and billed the test.
- Code
- L1
- Description
- Service already paid to another lab
Explanation
Updated October 26, 2026
L1 means this lab service was already paid to another laboratory, so it isn't paid again. Check which lab did the test.
What it means
L1 means OHIP has already paid another laboratory for this service for the patient. The same service is not paid twice.
Common causes
- The specimen was sent to, and billed by, another lab
- Duplicate billing for the same test
How to fix it
- Check whether another laboratory performed and billed the test.
- If your lab did the test and the other claim was wrong, gather the requisition and results.
- If you believe the decision is wrong, send a Remittance Advice Inquiry (RAI) through eSubmit, or on form 0918-84, within 7 months of the RA date, with supporting details.
Don't resubmit if
- Another laboratory performed the test.
- The line is already on your RA. Question it with an RAI, not a new claim.
How APEX handles it
APEX reads your error reports and remittance advice from MCEDT and lists claims rejected with this code in its Correction Centre for you to correct and resubmit. See how APEX works · Pricing