Most of these are still schedule 1s though, so if an insurance change forces you to a new GP you can get the prescription yanked - there's no guarantee of access to methylphenidate in the US, there aren't any over the counter methylphenidates and any other acquisition route would probably break the law (like buying it in Mexico or from a friend).

That said, at some point it's going to be worth it to just pay out-of-pocket for five minutes of your old GP's time to write a new script if things are dire... but the fact that this barrier can exist is troubling to me since being in that ADHD hole makes it so much easier to get over these barriers.