Guantanamo Transfer Prevention Act This bill prohibits the President from using Department of Defense (DOD) funds to transfer or release to or within the United States, its territories, or possessions Khalid Sheikh Mohammed or any other detainee who is not a U.S. citizen or member of the U.S. Armed Forces and is or was held on or after January 20, 2009, at United States Naval Station, Guantanamo Bay, Cuba, by DOD. Any contravening action by the President shall be without legal effect. No amounts authorized to be appropriated or otherwise made available for DOD for FY2016 may be used to: (1) close or abandon Guantanamo, (2) relinquish control of Guantanamo to Cuba, or (3) implement a material modification to the Treaty Between the United States of America and Cuba signed at Washington, DC, on May 29, 1934, that constructively closes Guantanamo.