OA 18 denial code means exact duplicate claims or services. Exact duplicate means submitted claim is duplicate of another claim in terms of date of service (DOS), Type of service, Provider number, procedure code or CPT, place of service (POS) and billed amount.
OA 18 comes in Medicare and in the case of other insurance, it comes as CO 18.
In this scenario, the patient receives the same service on the same day with two different providers or under different facilities. If the one provider received the payment prior to the second one then the insurance company deny 2nd claim as OA 18/ CO 18 or Duplicate claim/service.
How to Handle OA 18 Denial Code:
If services are provided by the same provider on the same day but more than one time in a day in that case we have to append modifier 76(Same day same provider), if the modifier is not appended then need to review by coding dept and if modifier already updated in claim in that case we have to send appeal with medical records for reprocessing the claim.
Scenario 2 –
Some times claim is already paid and the user is not able to find the exact information why it is denied as duplicate, in that case user should call the insurance company and take the information of the original claim like check number, claim number, dos, facility name, paid date and check bulk amount.