130drvr,
I think you may be confusing IMA tour with IMA position. There are IMA tours throughout AFRES, usually at the component commands, NAFS or at the Joint Commands and these are usually limited by a period. However, an IMA position is one that is part of the overall manning. I do not have to re-apply for my IMA position. I'm in it as long as I want, providing I get promoted or have met 2 promotion boards and have not been selected. I suppose I could promote myself out of the position and then have to search for another position with the appropriate grade. There is no MRD for an 0-4, unless you have not been promoted twice then it's approx 6 mos after your last board. For an 0-5 there is an MRD of 28yrs TFMS or 60yrs old whichever is 1st.