Payback is fairly straight forward.
In most cases you 1st payback period will be your Officer basic. This usually occurs between the 1st and 2nd year or the 2nd and 3rd year. The remainders are acutally used as clinical rotations. Your 45 day period will actually only be a 28 day medical rotation in most cases. You just do the rotation at a military institution, but it is essentially the same as any other 3rd or 4th year rotation, so time is not much of a factor.
If you are unable to take your training period then you do a school ADT. Where you essentially sit on your but at get paid anyways. They do this when you are not able to do training. I am currently doing this as my school has classes during the 1st and 2nd weeks of officer basic.
If you had to remediate a class I imagine the above scenario would take place and you would just take a school ADT
Very few fail and ones grades in undergrad usually have little to do with them failing. Sometimes its personal reasons, sometimes its just a change in how or where they study. Also this person may be one of those that rarely had to study in undergrad and still got great grades, that usually doesn't equate to much success in medical school. If you do fail the military re-evaluates. They may choose to drop your scholarship, but more than likely they will just suspend your scholarship and you will have to pay for the extra year in loans (although they may still give you the stipend, I am not sure)
