I'd say it straddles the border between 'common' and 'scarce.'
Seriously though. It's not really that uncommon to do this. The problem is that most residencies have only a few slots per year. You have to wait for a PGY-II slot to open, then apply there with lots of other residents who also want to start as a II or change programs. Look at the psychiatry clearinghouse (do a search here for the link) and you'll see what's available.