Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Form 10-K þ 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 o 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 1-33579 INTERDIGITAL, INC. (Exact name of registrant as specified in its charter) Pennsylvania 82-4936666 (State or other jurisdicti ...