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Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 U TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from FLORIDA ( State or other jurisdiction of incorporation or organization ) Form 10 - K 1301 Concord Terrace , Sunrise , Florida ( Address of principal executive offices ) Title of Each Class Common Stock , par value $ .01 per share Large accelerated filer Non - accelerated filer to X ☐ Commission file number 001-12111 MEDNAX , INC . ( Exact name of registrant as specified in its charter ) Registrant's telephone number , including area code ( 954 ) 384-0175 Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol MD Securities registered pursuant to Section 12 ( g ) of the Act : None 26-3667538 ( I.R.S. Employer Identification No. ) 33323 ( Zip Code ) 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 Exchange Act . Yes No 冈 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 Name of Each Exchange on Which Registered New York Stock Exchange 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 the definitions of " large accelerated filer , " " accelerated filer , " " smaller reporting company , " and " emerging growth company " in Rule 12b - 2 of the Exchange Act . 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 . □ 000 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 Exchange Act ) . Yes No × The aggregate market value of shares of Common Stock of the registrant held by non - affiliates of the registrant on June 30 , 2020 , the last business day of the registrant's most recently completed second fiscal quarter , was $ 1,251,965,108 based on a $ 17.10 closing price per share as reported on the New York Stock Exchange composite transactions list on such date . The number of shares of Common Stock of the registrant outstanding on February 12 , 2021 was 85,631,836 . DOCUMENTS INCORPORATED BY REFERENCE : The registrant's definitive proxy statement to be filed with the Securities and Exchange Commission pursuant to Regulation 14A , with respect to the 2021 Annual Meeting of Shareholders is incorporated by reference in Part III of this Form 10 - K to the extent stated herein . Except with respect to information specifically incorporated by reference in the Form 10 - K , each document incorporated by reference herein is deemed not to be filed as part hereof .