How come its more than 5 month?? Lets say if you leave around 1st week of January. Summer starts sometime around May. Then you can return around end of April or 1st week of May. Then do the math. January to May is around 4 month. The catch over here is If you are going to use your current I-20 then you have to return back to US before 5 month and take Summer class as a full time student which is 12 credit hour. If you do so, I dont think that you'll have any problem. I'm doing the same thing right now. I'm leaving around January and returning back around May and take summer class. If you have questions go to the international advisor. That would be your best option. If you really wanna take a semester off then act fast. Because you dont have much time. To take a semester break, your SEVIS has to be canceled temporary. So it takes a little time for that. So hurry up and talk to the advisor.