There are several types of involuntary separation. Basically, this is anytime you don't put in your papers after your term of active duty or your enlistment is up. It could be for a myriad of reasons such as: conduct, medical disqualification, and the crowd favorite....force reduction (usually limited to certain career fields). Understand that the intitial enlistment period of 6 years has no bearing whatsoever on whether you get put on the street, especially if it is for conduct or medical.

About three years ago, the Air Force did some force reduction and decided to give some Lt's thier walking papers. It was based on what career field they were in (no pilots or navs I believe) and how they were rated by thier commanders. I think the people selected for this are given some sort of pay or severance as they leave to somewhat compensate them.

The year after they reduced all those Lt's they wanted to reduce some more but in a larger range of career fields and ranks so this time they offerred a VSP or Voluntary Separation Program. It allowed people to volunteer for separation for a bonus payment that was based on their rank and time in service. It was pretty effective, but not everyone who volunteered for this was granted the separation which can make for a sticky situation with your commander come time for that next assigment, promotion, or awards package.

The bottomline is that the needs of the military service you are in always come first. However also understand that involuntary force reduction doesn't happen all that often, at least not in the Air Force. I think that last time the Air Force reduced previous to these recent reductions was post Desert Storm in the early 90's.

I don't know about the Guard/Reserve except to say that unless the unit has been affected by the latest BRACC (Base Realignment and Closure Committee) then you probably won't have any problems (unless its conduct or medical, then you will always have problems).