If I may, fortunately I haven't personally gone through the medical release part of it, but for a soldier who wants to be medically released or does not want to, yes, the time can really vary, basically depending on your unit. If they feel that they still need you, they could hold on to you and they could draw out that frame. If they feel that they don't want you anymore, you can be out within 30 days.
On December 6th, 2012. See this statement in context.