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

Insurance will deny with CO 4 Denial Code – The procedure code is inconsistent with the modifier used or a required modifier is missing, whenever the CPT code billed with an incorrect modifier or the necessary modifier is absent in the submitted claim.

Let us see below examples to understand the above denial code:

Example 1:

Assume provider has performed the electrical stimulation procedure (invasive) to aid bone healing for patient name John.

In this example we have to report the claim with the procedure code 20975. If suppose provider submits this procedure code along with modifier 51, then claim will be denied as CO 4 Denial Code – The procedure code is inconsistent with the modifier used or a required modifier is missing. Because as per CPT book guidelines for procedure code 20975 modifier 51 is exempted, so we should not report procedure code 20975 with modifier 51.

Example 2:

Bone graft codes are reported with (through CPT 20900 to CPT 20938).

As per the guidelines for bone graft codes, we should not report with modifier 62 (two surgeons). If we report then claim with modifier 62 for bone graft codes, then claim will be denied as CO 4 denial code.

Note: Similarly some procedures need to be reported with modifier, those claims will be denied with the same denial code if it’s not reported. So coding team need to be careful while coding some procedures along with modifiers.

Let us see first what is Modifier in medical billing.

Modifier:

Modifier is a 2 digit code added to the procedure code, if there is any alteration/specification of the treatment/services rendered to the patient.

When claim denied with CO 4 Denial code – The procedure code is inconsistent with the modifier used or a required modifier is missing, need to take the following steps to resolve:

• Review other date of service for this patient to determine if same CPT codes were paid previously with the modifier in the claim or without the modifier. If yes, you have to reach out insurance company claims department and send the claim back for reprocessing.
• After reviewing application if you found that previous date of service were not paid, send the claim to coding team to review the claim and correctness of CPT code/Modifier. If coding team says the claim billed is correct, then reprocess the claim by reaching out insurance company claims department.
• If insurance rep refuses to send the claim back for reprocessing, you have rights to submit an appeal with medical records.
• Coding team suggests additional modifiers, update the correct modifiers and resubmit the claim as corrected claim.
• If previous notes states appeal is already sent, call the insurance and follow up on appeal status.

What are the questions need to ask with representative, when you reach out claims department for the CO 4 Denial code – The procedure code is inconsistent with the modifier used or a required modifier is missing:

• Get the Claim received date and denial date?
• First verify whether submitted modifier is invalid or any modifier is missing?
• Check the application to verify other date of service of the same patient, to see same procedure codes with or without modifier were paid previously. If yes send the claim back for reprocessing.
• If no, check with representative and try to get appropriate modifier missing or the valid modifier for that procedure code?
• If rep provides, update and resubmit the claim as corrected claim.
• If rep doesn’t provide, get the appeals details/corrected claim address and time limit to resubmit the claim as corrected claim. (Note: Send this to coding team to review and take necessary action as per their suggestion).