Error report · Referral & provider
OHIP error code AC4
Unaccepted Referral Number. Not 6 numerics Equal to the Practitioner billing number Referring number is 722900-744292 (Nurse Practitioner (NP)) and FSC is not eligible for NP referral. Referring number is 700000-722899 (Midwife (MW)) and FSC is not eligible for MW referral.
What AC4 means
The Ministry of Health’s official wording for AC4 is: “Unaccepted Referral Number. Not 6 numerics Equal to the Practitioner billing number Referring number is 722900-744292 (Nurse Practitioner (NP)) and FSC is not eligible for NP referral. Referring number is 700000-722899 (Midwife (MW)) and FSC is not eligible for MW referral..”
This code appears on your Claims Error Report (downloaded through MCEDT). It means the claim was rejected at submission and was never adjudicated for payment — fix the issue below and resubmit the claim.
How to fix AC4
Correct the referral number - it must be 6 digits, not your own billing number, and from a provider eligible to refer for this code (note the NP and Midwife referral limits) - then resubmit.
Referral and provider codes relate to the referring or rendering provider number, specialty restrictions, or referral requirements attached to the fee code. Verify the provider numbers on the claim and whether the code requires a valid referral.
Related codes
- A36Claimed by Other Practitioner
- A4DInvalid specialty for this service code
- ARFMissing Physician Referring Number
- ARPReferring Physician Number Required
- EG1Group not Eligible
- ENPInvalid FSC for Nurse Practitioner (NP)
- EP5Incorrect FSC for Group Type
- EQ1Clinic/Doctor Not on File - Practitioner not registered with OHIP
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Code meaning per Ontario Ministry of Health — Error Report Rejection Conditions / Error Codes (December 2022). The suggested action is general information for Ontario physicians, not billing, legal, or tax advice — codes and rules change, so verify against the current Ministry of Health documents before relying on a claim.