I wear 15 too. They are non existent in any stores for trying on. I just get them on the internet and hope they work. I am not injury prone or particular about specs at all so I can get away with this. I don't know about your situation. The good thing is that basically every common running shoe is at least made in 15. So there you go, I didn't help you at all. Actually Ross and TJ Max stores have 15s usually, but it will be an extremely limited selection for trying on.