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Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 ANNUAL REPORT PURSUANT TO SECTIONS 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 FORM 10 - K ( Mark One ) [ X ] ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended March 31 , 2021 OR [ ] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from Texas ( State or other jurisdiction of incorporation or organization ) Commission File Number : 814-00061 CAPITAL SOUTHWEST CORPORATION ( Exact name of registrant as specified in its charter ) 5400 Lyndon B Johnson Freeway , Suite 1300 , Dallas , Texas ( Address of principal executive offices ) to Title of Each Class Common Stock , $ 0.25 par value per share Large accelerated filer Registrant's telephone number , including area code : ( 214 ) 238-5700 Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol ( s ) CSWC 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 X Accelerated filer 75-1072796 ( I.R.S. Employer Identification 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 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 75240 ( Zip Code ) Name of Each Exchange on Which Registered The Nasdaq Global Select Market Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , 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 . Non - accelerated filer X 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 effective 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 .