It all depends, on what I am not sure. I have known some people that have done 4 years of ATC in the military, then moved on to the FAA without going through the FAA school in Oklahoma. I have known others that got hired, but had to go to the school in Oklahoma. It is still not a bad deal though, the FAA pays you while you are going through the school, and the school is easy because you already know how to work air traffic. All military rated controllers are rated as far as the FAA is concerned. There is no conversion of any sort. In fact, if you have a CTO (certified tower controller) for a military tower, it is an FAA certification. The military is not a bad way to go if you can get in as an air traffic controller, do your 4 years and get out before you turn 31.