The balancing requirement for a secondary claim is the same as the balancing requirement for a primary claim see section 1.10.2.1.

As stated in section 1.10.2.13, Secondary Payment Reporting Considerations, there are additional requirements when reporting a secondary claim. Those include usage of CARC 23 with Claim Adjustment Group Code OA which reports the contractual reductions and paid amount from the primary payer in a way that does not result in reposting by the provider. Section 1.10.2.13 also identifies requirements for the secondary payer to report any additional contractual reductions or remaining patient responsibility adjustment. The secondary payer must balance, and follow all of the other instructions in this section. Examples of reporting COB payment can be found in section 3.3

Reporting the entire submitted charge as an OA*23 adjustment when that doesn't represent the related primary adjudication information is not consistent with the guide.

See RFI 1656 Primary Payer Impact and RFI 1696 Secondary payer CAS coding for more information on this topic.