Medicare and revision

Does anyone have any experience with Medicare and having an RNY revision, or better yet a revision to DS?  Is there a code I can give them?  No one there seems to know anything... 

Medicare requires that you have your surgery at a Center of Excellence.  If you go thru them they know how to present your request and all the right codes.  I don't think Medicare covers DS unless they've approved it recently. 

Thanks for your reply!  It does appear to be on their list now, and the surgeon I am going to see is with a COE and knows I have Medicare and am seeking the DS.  Hopefully this is all correct!!!