First, easier if in IRR, but remember your commissioned service continues even with a "break" in service. So, you have 10 years AD, but now have 13 years of Total Years Commisioned Service meaning things like you might be ready for the Major's board; you might have to make Lt Col to get 20 good years. A good friend had a 5 year break and had to make LtCol, for example. Not usually a problem and well worth doing.

Second, do so before 5 years out, then the unit has to run a FEB to get you back on flying status. Not difficult, I've done one, but some commanders don't want to deal with it.

Third, related to first, you have to have your last 6-8 years in the Reserves or ANG, all meeting the participation requirements to be retirement eligible.

GF