Multiple arthroscopie procedure

When Medicare is paying under the "family" guidelines, should they any of the codes be paid at 50% of the difference? For example, I have CPT codes 23412, 23430, 29826 and 29824. They paid 23412 as primary, 23430 and 29826-59 at 50% of the allowable and 29824 at 50% of the difference.

Thanks