I got my green card in June, 2009. I took 5 short travels from 2009 to 2012 (total 165 days, no trip lasted more than 3 months). My future travel will be as followings: Mar 15, 2013 - Sept 01, 2013 (165 days) and Oct 02, 2013 - Feb 01, 2014 (120 days). I plan to file N-400 on March 20, 2014 (90 days before 5 years). As you can see, since obtaining the green card, I physically stayed in the USA for more than 30 months and did not take any trip that is 180 days long. However, I am only presence in the USA for 105 days in 2013. Will U.S.C.I.S. use this as a denial ground? Can I file N-400 on March, 2014 (40 days after my return to the USA from a 4 months travel)? Or do I have to file 90 days after my return?