Washington, D.C. 20549 FORM 10-K Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended March 31, 2019 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 1-13449 QUANTUM CORPORATION (Exact name of Registrant as specified in its Charter) Delaware 94-2665054 ( State or other ju ...