The 2013 2500 frame is a carry-over from 2012. The 2013 3500 frame is new and has pockets welded to the frame rails for the Ram-produced inserts that come in the hitch prep package, a $400 option. I suspect the aftermarket will come up with a way to put a fifth wheel hitch on a 2013 3500 that does not have the factory package/inserts. B&W has already produced a ball mount kit for the gooseneck, for those with the 3500 frame but no prep package. Meanwhile, your 2500 should accept any hitch setup for the 2012.