Page 1

Table of Contents ( Mark One ) UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON , D.C. 20549 FORM 10 - K ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT For the transition period from to Delaware ( State or Other Jurisdiction of Incorporation or Organization ) Securities registered pursuant to Section 12 ( b ) of the Act : Title of Each Class Common Stock , par value $ .01 per share Large accelerated filer > Commission file number : 1-34392 Plug Power Inc. ( Exact Name of Registrant as Specified in Its Charter ) None . Trading Symbol ( s ) PLUG Accelerated Filer Securities registered pursuant to Section 12 ( g ) of the Act : None Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes No Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 ( d ) of the Act . Yes No Indicate by check mark whether the registrant ( 1 ) has filed all reports required to be filed by Sections 13 or 15 ( d ) of the Securities Exchange Act of 1934 during the preceding 12 months ( or for such shorter period that the registrant was required to file such reports ) , and ( 2 ) has been subject to such filing requirements for the past 90 days . Yes No 22-3672377 ( I.R.S. Identification Number ) 968 ALBANY SHAKER ROAD , LATHAM , NEW YORK 12110 ( Address of Principal Executive Offices , including Zip Code ) ( 518 ) 782-7700 ( Registrant's telephone number , including area code ) Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S - T ( §232.405 of this chapter ) during the preceding 12 months ( or for such shorter period that the registrant was required to submit such files ) . Yes No Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , a smaller reporting company , or emerging growth company . See the definitions of " large accelerated filer , " " accelerated filer , " " smaller reporting company , " and " emerging growth company " in Rule 12b - 2 of the Exchange Act . Name of Each Exchange on Which Registered The NASDAQ Capital Market Smaller reporting company Emerging growth company If an emerging growth company , indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13 ( a ) of the Exchange Act . Non - accelerated filer Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404 ( b ) of the Sarbanes - Oxley Act ( 15 U.S.C. 7262 ( b ) ) by the registered public accounting firm that prepared or issued its audit report . Yes No Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Exchange Act ) . Yes No The aggregate market value of the registrant's voting and non - voting common stock held by non - affiliates of the registrant was approximately $ 2,733,184,540 based on the last reported sale of the common stock on The NASDAQ Capital Market on June 30 , 2020 , the last business day of the registrant's most recently completed second fiscal quarter . As of May 6 , 2021 , 568,317,504 shares of the registrant's common stock were issued and outstanding . DOCUMENTS INCORPORATED BY REFERENCE