Do you mean orthotics that you insert into shoes or "orthotic shoes"? I have no experience with 'orthotic shoes' but lots of experience with custom orthotics and DAFOs. My experience is that you should not get them from a podiatrist (who could prescribe them) but from an orthotist who specializes in cast/creating/fitting them. We've had very poor results with podiatrists.
I've got 2 kids who need the custom orthotics and 1 kid who does very well with the semi-custom ones that Shoe Train has. We drive from Alexandria just for that reason - and to get shoes that fit with them.