So, DH qualifies for both GI Bills, he hasn't switched it yet to Post 9/11. My question is can you use the Montgomery GI Bill while on active duty, or is that just one of the perks of the Post 9/11? Also,if he did it this way, since he used most of his GI Bill already, once he maxed it out would he still qualify for the additional 12 months of Post 9/11?