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Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION 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 , 2020 TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from Commission File Number 001-36569 LANTHEUS HOLDINGS , INC . ( Exact name of registrant as specified in its charter ) Delaware ( State or other jurisdiction of incorporation or organization ) 331 Treble Cove Road , North Billerica , MA ( Address of principal executive offices ) to Title of Each Class Common Stock , $ 0.01 par value per share LNTH 35-2318913 ( I.R.S. Employer Identification No. ) Registrant's telephone number , including area code : ( 978 ) 671-8001 Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol ( s ) 01862 ( Zip Code ) Securities registered pursuant to Section 12 ( g ) of the Act : None Name of Each Exchange on Which Registered NASDAQ Global Market No p No p Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes 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 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 p No Indicate by check mark whether the registrant has submitted 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 þ No □ Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , or a smaller reporting 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 р Accelerated filer Non - 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 . □ 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 . Indicate by check mark whether the registrant is a shell company ( as defined by Rule 12b - 2 of the Act ) Yes No p The aggregate market value of the registrant's common stock held by non - affiliates of the registrant on June 30 , 2020 was approximately $ 947.4 million based on the last reported sale price of the registrant's common stock on the NASDAQ Global Market on June 30 , 2020 of $ 14.30 per share . As of February 19 , 2021 the registrant had 66,968,382 shares of common stock , $ 0.01 par value , issued and outstanding . DOCUMENTS INCORPORATED BY REFERENCE Listed hereunder are the documents , portions of which are incorporated by reference , and the parts of this Form 10 - K into which such portions are incorporated : The Reg ant's Definitive Proxy Statement for use in connection with the Annual Meeting of Stockholders to be held April 27 , 2021 , portions of which are incorporated by reference into Parts II and III of this Form 10 - K . The 2021 Proxy Statement will be filed with the Securities and Exchange Commission no later than 120 days after the close of our year ended December 31 , 2020 .