I am working with a payer who refuses to include a Claim Adjustment Reason Code '23' CAS segment in an 835. I have provided them with information from this site trying to convince them an 'OA-23' adjustment is required. They are stating they are not required to provide this information in the 5010 835. I have access to the corresponding paper remit from the payer and it clearly shows how much other insurance has already paid to me on these charges. Is a payer who is aware other insurance has paid a portion of the total charges that I am now billing to that payer required to supply a CAS segment with an 'OA-23' adjustment acknowledging the amount paid on those charges by other insurance? In the absence of this adjustment, the payer is adjusting the total billed amount less their payment to 'CO-45' and after posting my patient account has a large credit balance. If the 'OA-23' adjustment is required, is that requirement version specific or does it apply to all versions of the 835 transaction set?
In the 005010X221A1 guide, section 1.10.2.13 explicitly states “Report the ‘impact’ in the appropriate claim or service level CAS segment with reason code 23 (Payment adjusted due to the impact of prior payer(s) adjudication including payments and/or adjustments.), and Claim Adjustment Group Code OA (Other Adjustment). Code OA is used to identify this as an administrative adjustment.” So the payer must use OA 23 instead of CO 45 to show the previous payers impact. As for the version specific question, all versions of the guide, including the 5010 version, contain this language requiring OA-23.
Please refer to RFI 1696 for additional information. One line of particular note for your provider is "All payers are encouraged to look at these requirements from the perspective of the processing by the provider, and delivering administrative simplification".