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( Mark One ) ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the year ended December 31 , 2020 TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 FORM 10 - K Delaware ( State or other jurisdiction of incorporation or organization ) Non - accelerated filer For the transition period from to Commission File Number : 001-36571 T2 Biosystems , Inc. ( Exact name of registrant as specified in its charter ) 101 Hartwell Avenue , Lexington , MA ( Address of principal executive offices ) Title of each class Common Stock , par value $ 0.001 None . Trading Symbol ( s ) TTOO 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 of 1933 , as amended . 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 Securities Exchange Act of 1934 , as amended . NO > Indicate by check mark whether the registrant ( 1 ) has filed all reports required to be filed by Section 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 Registrant's telephone number , including area code : 781-761-4646 Securities registered pursuant to Section 12 ( b ) of the Act 20-4827488 ( I.R.S. Employer Identification No. ) 02421 ( Zip code ) Name of each exchange on which registered The Nasdaq Global Market 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 an emerging growth company . See definitions of " large accelerated filer , " " accelerated filer " " smaller reporting company , " and " emerging growth company " in Rule 12b - 2 of the Exchange Act . Large accelerated filer Accelerated filer 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 . YES □ 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 . DOCUMENTS INCORPORATED BY REFERENCE Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Exchange Act ) . Yes No 区 As of June 30 , 2020 , the last business day of the registrant's most recently completed second fiscal quarter , the aggregate market value of the registrant's common stock held by non - affiliates was approximately $ 147.9 million based on the closing price for the common stock of $ 1.27 on that date . Shares of common stock held by each executive officer , director , and their affiliated stockholders have been excluded from this calculation as such persons may be deemed to be affiliates . This determination of affiliate status is not necessarily a conclusive determination for other purposes . The number of outstanding shares of the registrant's common stock on March 26 , 2021 was 148,491,673 . 0