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☐ 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 26 , 2020 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 1-6770 Title of each class Common Stock , $ 0.01 Par Value FORM 10 - K Delaware ( State or other jurisdiction of incorporation or organization ) 150 Schilling Boulevard Suite 100 Collierville Tennessee ( Address of principal executive offices ) MUELLER INDUSTRIES MUELLER INDUSTRIES , INC . ( Exact name of registrant as specified in its charter ) Large accelerated filer Non - accelerated filer Emerging growth company 25-0790410 38017 ( Zip Code ) Registrant's telephone number , including area code : ( 901 ) 753-3200 ( I.R.S. Employer Identification No. ) Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol MLI □□ Indicate by check mark whether 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 a 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 , or a smaller reporting 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 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 . Yes > No Indicate by check mark whether the Registrant is a shell company ( as defined in Rule 12b - 2 of the Act ) . Yes No The aggregate market value of the voting and non - voting common equity held by non - affiliates computed by reference to the price at which the common equity was last sold , or the average bid and asked price of such common equity , as of the last business day of the Registrant's most recently completed second fiscal quarter was $ 1,346,053,993 . The number of shares of the Registrant's common stock outstanding as of February 19 , 2021 was 57,115,648 excluding 23,067,356 treasury shares .