UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ý Annual Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 For the fiscal year ended December 31, 2018 OR ¨ Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to Commission File Number: 1-33146 KBR, Inc. (Exact name of registrant as specified in its charter) Delaware 20-4536774 (State of incorporation or organization) (I.R.S. Emplo ...