Denial Code CO 4 – The procedure code is inconsistent with the modifier used or a required modifier is missing.

When it comes to getting the claims from your insurance, it is quite a lengthy affair. One has to be specifically clear about what the requirements are and ensure that there is no kind of misinformation mentioned. CO 4 Denial code represents procedure code is not compatible with the modifier used in services.

Modifier is a 2 character alpha numeric or numeric code that are used with CPT codes to indicate that a performed service has been altered by some specific circumstance but has not changed in its definition or code.

Please take the below action, when you receive the Denial Code CO 4.
1. First review and check to see with the coding team that the used modifier is in-consistent or required modifier is missing.
2. Update the appropriate modifier and resubmit the claim (Some insurances, claims should be resubmitted as corrected claim).
1. If you find the claim submitted with an appropriate modifier, but the insurance denied the claim incorrectly. Then the next step is to reach claims department and send the claim back for reprocessing.
2. If they disagree then the final step is to appeal the claim with supporting documents.

You can reach the claims department with the following questions to resolve the below denial:
• May I know the Claim received date?
• May I know the claim denied date?

• May I know to which procedure code the modifier is Inappropriate or missing?
• May I know the appropriate modifier for the procedure code billed?
If Representative provide the appropriate modifier
Call telephonic re-opening line update the modifier and send the claim back for reprocess (Medicare) or else for few insurances corrected claim should be resubmitted.
If they won’t provide
1. Check with coding team and resubmit the claim with appropriate modifier or missing modifier.
2. If Coding team states already submitted modifier is appropriate and claim denied incorrectly, then you may appeal the claim with supporting documents.
So try to collect the appealing address and time limit or fax# to appeal the claim.

• May I know the claim#
• May I know the call ref#

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