For the vast majority probably not, it really depends on the individual. You can get promoted in the IRR, attend schools, annual training, short tours, etc., its really up to the individual on how active they want to be while in the IRR or if they are just "sitting" their until their time runs out. People often choose the IRR because you can manage your commitment to fit your schedule and aren't tied to a specific schedule as you would in a unit. I have seen officers go their because they were promoted and could not find a position in the new grade and shopped around until they found one or waited until another officers tenure was up and replaced them in the same unit.
There is not a black and white answer to this. If all you are doing is sitting in the IRR waiting for your military service obligation to end, it kind of counts since it fulfills that. However, you still get 15 membership points and in the Army at least, you can request training and do other things to get a good year in the IRR. In 2012, I had an opportunity through my reserve unit to deploy to Afghanistan. However, they required me to transfer to the IRR so I would not count against them in their numbers while deployed. So I submitted the request and transferred to the IRR. I served over a year on active duty while assigned to the IRR control group. So for me, that time does count. However, in most cases, IRR time just rounds out your MSO and I would not brag about counting that time as service to any other Veteran.
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