I am an American grad but a non-US citizen (Canadian citizen). I will be starting residency in July. If I get H1B visa for residency training is it possible to switch to J1 for fellowship? The reason that I ask this is because I have heard that alot more programs offer J1 rather than H1 for fellowship so it'll be very difficult to get a fellowship position if I'm on H1. The reason that I don't want to go on J1 right away for residency is because I am not entirely sure whether I want to do a fellowship. Thanks.