An updated description of planned GMD flight tests (last update was my post of April 12, 2015) as best I can reconstruct them. Between now and mid-2021, it appears that MDA plans five intercept and one non-intercept test of the GMD system.
FTG-15 (1Q FY 2017). This is scheduled to be the first intercept test since FTG-06b in July 2014. It will be the first GMD intercept test against an ICBM-range target (range greater than 5,500 km). The target will include countermeasures. FTG-15 will also will be the first flight and intercept test of the new production CE-II Block-I version of the Exo-Atmospheric Kill Vehicle (EKV) and the first flight test of the upgraded C2 booster. According to Admiral Syring, in this test “…we’re getting now out to the long-range and closing velocities that certainly would be applicable from a North Korean or Iran type of scenario.” 
FTG-15 (Image source: MDA)
Posted by mostlymissiledefense on April 20, 2016
This is an updated list (previous version was June 16, 2015) of claims by U.S. government officials about the effectiveness of the U.S. Ground-Based Midcourse (GMD) national missile defense system. It adds four additional claims (#33, #34, #35 and #36).
(1) September 1, 2000: “… I simply cannot conclude, with the information I have today, that we have enough confidence in the technology and the operational effectiveness of the entire NMD system to move forward to deployment. Therefore, I have decided not to authorize deployment of a national missile defense at this time.” President Bill Clinton, at Georgetown University, September 1, 2000.
(2) March 18, 2003: “Effectiveness is in the 90% range.” Edward Aldridge, Undersecretary of Defense for Acquisition, Technology and Logistics.
Posted by mostlymissiledefense on April 14, 2016