Wiki Mod 59 vs Modifier XS

[MScolamiero]

I know that as of January 1, 2015 Medicare added the more specific modifiers to be used in place of modifier 59 but they are still accepting the modifier 59 if one of the "specific" modifiers doesn't fit the situation. I also know that Medicare automatically adds a modifier 51 onto CPT codes that they view as multiple procedures being done on the same DOS. My question is has anyone noticed a different reduction in reimbursement when they use modifier 59 vs the modifier XS? Medicare is reducing my payments on CPT code 76770 because it was done on the same day as 76700 but when the modifier 59 was used they reimburse $101.12 yet when modifier XS was used on the same CPT code they only reimbursed $58.31. I can't find any documentation to explain why there is a difference in the reimbursement. Anyone have any insight? Thanks!!