Claim Denied for CO-163 Primary EOB is Required

Claim denied CO 163 for primary EOB
Denial Code CO 163: Attachment referenced on the claim was not received.


Denial Code CO-163: Attachment referenced on the claim was not received

Many people have access to health care coverage through a primary insurance and a secondary insurance plan. Having more than one insurer covering medical costs can have its benefits.

Primary insurance is a health insurance plan that covers a person as an employee, subscriber, or member. Primary insurance is billed first when you receive health care. For example, health insurance you receive through your employer is typically your primary insurance.

Secondary insurance is a health insurance plan that covers you in addition to your primary insurance plan. Typically, secondary insurance is billed when your primary insurance plan is exhausted and may help cover additional health care costs. For example, if you already have insurance through your employer and choose to enroll with your spouse’s health insurance plan (if allowed), that coverage would become your secondary insurance.

What is an EOB?

EOB: Explanation of Benefits

An EOB is a statement from your health insurance plan describing what costs it will cover for medical care or products you’ve received. The EOB is generated when your provider submits a claim for the services you received.

Call Scenario:

May I get the denial date?
Check your system, the insurance on which you have made the call is listed as primary or secondary insurance
Primary Insurance Secondary Insurance
Could you please tell me which insurance is the primary insurance Check if payment from primary insurance is received/processed by primary that can be billed to secondary
Rep provided Yes Rep provided No IF Yes IF No
What is the policy id, payer id & mailing address for primary insurance May I have the claim# & call ref#) Check box# 29 in CMS 1500 form if paid amount of primary insurance is available, if yes then it means that primary paid details already sent to insurance Follow up with primary insurance & work claim as per primary insurance  status


IF rep says it still not received (Secondary Insurance)

What is the Fax# or mailing address & time limit to send the EOB?

IF Rep sent claim back for reprocessing

What is the TAT for reprocessing?

At the End

May I have the claim# & call ref#


Important Note:

  • If rep does not provide primary insurance details then checked in system if there is any other insurance available or patient payment history has any other insurance as primary, if yes then check eligibility for that insurance and resubmit the claim to that payer if policy is active as primary or else release the claim to patient if policy is inactive or no other insurance information available.
  • You can also check payer web portal to get primary insurance details if access is available.
  • When rep provides the primary insurance information and you have web portal access for primary insurance then always verify eligibility through website, there could be possibility that primary insurance is inactive on dos then ask insurance to reprocess the claim.
  • When rep provides all details of primary insurance then you can update that insurance as primary and make current insurance as secondary insurance and resubmit the claim to primary insurance.
  • If claim is already paid by primary insurance and primary paid information does not go through on first attempt then you can resubmit the claim and check the claim form whether paid details is now available or not, if it is still missing then send EOB through fax or mailing address.
  • If time limit to submit primary EOB is already passed then write off the charge or follow your client instructions.
  • Always check remark code given with the denial reason, sometimes it provides the exact reason for denial that could differ. So follow AR scenario tool to work the exact denial.

Learn More…

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Denial Reason Code PR B9: Patient is Enrolled in a Hospice



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