X0306 4 2017-02-27 0 0000866121 ORBITAL ATK, INC. OA 0001557458 Culbertson Frank L. Jr. C/O ORBITAL ATK, INC. 45101 WARP DRIVE DULLES VA 20166 0 1 0 0 Executive Vice President Common Stock 2017-02-27 4 A 0 2138 0 A 24880 D Common Stock 1041 I By 401(k) Plan Employee Stock Option (right to buy) 93.51 2017-02-27 4 A 0 4086 0 A 2027-02-27 Common Stock 4086 4086 D Includes 19 shares acquired under the Orbital ATK, Inc. 2016 Employee Stock Purchase Plan on December 30, 2016. Since the date of the reporting person's last Form 4 report, he transferred 696 shares of Orbital ATK common stock held in the Orbital ATK, Inc. 401(k) Plan to his ex-spouse pursuant to a domestic relations order. The reporting person no longer reports as beneficially owned any securities owned by his ex-spouse. Options become exercisable in three equal annual installments beginning February 27, 2018. /s/ Richard N. Osborne, Attorney-in-Fact 2017-03-01