Well, here is the other mystery. My problem disc has always been refered to as L4/L5 up until an x-ray report from early this year. It is now being refered to as L5/S1. A couple reports have indicated a transitional segment (?)which I think is where the confusion began. The NS seems to be sure it's L5/S1.
But it is causing major problems as my comp carrier fighting that it's a new injury. Needless to say, they are becoming difficult to deal with. They don't want to take responsibility.