Wiki Modifier 51 and Medicare


True Blue
Charlotte, NC
Best answers
I work for a GI practice and we just received a MCR EOB. There were three procs done a 43249 and a 43239 and a colon. The 43239 had a mod 59 attached. When we received the eob back from MCR-they had attached a mod 51 to both upper GI endo's. They were paid as such also.

Has anyone else seen this before? And could you let me know why?

This was a question once presented at a Medicare meeting I attended. The response was...some charge entry staff applied modifier 51 to the wrong procedure code. As a result, the code with the highest RVU's had the 50% reduction taken rather than the lesser one.

Our region prefers that we do not apply the modifier 51. They have edits in place to automatically add the 51 modifier so that the correct adjustments are taken.

Last edited:
I code for GI procedures and use modifier 51 because I am instructed to do so by my supervisor, however, modifier 51 is not needed for Medicare. You will see it added on the remittances. They attach the modifier 51 where appropriate to apply the multiple procedure reductions and endoscopic rule reductions.

For Cahaba MC (AL, GA, MS), "modifier 51 is not required for billing purposes. The carrier will assign the multiple procedure modifier if appropriate based on the services billed." Per conversations, with many of the customer service rep. they instruct me not to use 51 due to the claim may be denied. This is documentated on their website,, in the search field put modifier 51.

Hope this helps, :)
codegirl 0422
Last edited: