They completely cover moving costs, but won’t cover losses on a house, but something may be the works for that.
As for me, I’m currently at a civilian hospital for fellowship (Harbor UCLA). When I’m finished next Summer there is only 4 places they can send me, SD, Bethesda, Portsmouth or Okinawa. Because cross-country moves are so expensive we’re “encouraged” to seek training sites near where we want to go, so I chose Harbor. Unfortunately the needs of the Navy sometimes trump logic. My detailer has told me that there is someone at Bethesda who is eligible for retirement in Nov 09. If she gets out I go there, if she stays in I go to SD. It’s a bit frustrating having your career dependent upon someone else’s decision, but that is the reality of a military career, medical or otherwise.