I have had my ICD for about 3 1/2 years now. I had some slight movement with it the first few months but it pretty much stayed where it was implanted. It has stabilized since then and firmly in place in my upper left chest about 3-4" below my collar bone and the same distance over from my arm pit. It was uncomfortable the first several months and quite pronounced visually. That has settled down since then and isn't nearly as noticeable as it used to be.