UNITED STATES SECURITIES AND EXCHANGE COMMISSION Enphase Energy, Inc. (Exact name of registrant as specified in its charter) Washington, D.C. 20549 Form 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 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: 001-35480 Delaware 20-4645388 (State or other jurisdiction o ...