How hard is it to switch from active to reserves, and how far out from my EOS should I start the process?

It does not hurt to speak to the local Recruiter sooner than later. It differs for every branch, but you are better to hear, "Come back in 6 months" than, "oh, sorry, you *just* missed the cut-off for processing". Since the Recruiter has to find you a Reserve billet, that may take time. I deal directly with the MacDill In-Service Recruiter, that way I can give him the billet number to transfer AD to our program, etc. Good luck!!

You should start about 6 mos before your ETS. Just find a unit that has a vacancy, you qualify for and if they will they agree to accept you. You can also let a Reserve Recruiter do it all for you. It's very easy.

I do not know the current process because I've been retired many years, but I do know that you want to have your Reserve paperwork completed before your term of enlistments ends, so you don't have a break in service. Make sure your enlistment in the Reserves starts the very next day after your active service ends. Even if its a year out, I would start the process now. Better to be too soon than too late. I transferred from active, to Guard to Reserves, but never had a break in service for 20 years. It makes a difference regarding your clearance, retirement, etc.