Originally Posted by Sledge2005

Are you sure? I'm fairly certain that doing a military resideny will count toward your IRR time, since it's active duty and technically counts as payback (although you also accrue time simultaneously).

So if you sign up for a four year contract (also hence also owe an additional 4 years IRR), and then do a 4 year military residency, you'll come out of residency still owing 4 years active duty, but no longer owing any additional IRR time beyond that.