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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 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 : 001-32269 EXTRA SPACE STORAGE INC . ( Exact name of registrant as specified in its charter ) Maryland ( State or other jurisdiction of incorporation or organization ) Title of each class 2795 East Cottonwood Parkway , Suite 300 Salt Lake City , Utah 84121 ( Address of principal executive offices and zip code ) 20-1076777 ( I.R.S. Employer Identification No. ) Registrant's telephone number , including area code : ( 801 ) 365-4600 Common Stock , $ 0.01 par value Securities Registered Pursuant to Section 12 ( b ) of the Act : Trading symbol EXR Name of each exchange on which registered New York Stock Exchange 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 15 ( d ) of the Act . Yes No x 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 x 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 x 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 . Large accelerated filer Non - accelerated filer ☑ ☐ Accelerated filer Smaller reporting company Emerging growth company ☐ ☐ ப 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 . X Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Exchange Act ) . Yes ☐ No " . The aggregate market value of the common stock held by non - affiliates of the registrant was $ 11,637,515,440 based upon the closing price on the New York Stock Exchange on June 30 , 2020 , the last business day of the registrant's most recently completed second fiscal quarter . This calculation does