Page 1

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 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 : 001-38468 Inspire Medical Systems , Inc. ( Exact name of registrant as specified in its charter ) Delaware ( State or other jurisdiction of incorporation or organization ) 5500 Wayzata Blvd. , Suite 1600 Golden Valley , MN ( Address of principal executive offices ) ( 844 ) 672-4357 ( Registrant's telephone number , including area code ) Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol ( s ) INSP Securities registered pursuant to Section 12 ( g ) of the Act : None Title of each class Common stock , $ 0.001 par value ( I.R.S. Employer Identification No. ) Accelerated filer 26-1377674 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 ® 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 Non - accelerated filer 55416 ( Zip Code ) Name of 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 . Large 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 in Rule 12b - 2 of the Act ) . Yes No > As of June 30 , 2020 , the last business day of the registrant's most recently completed second fiscal quarter , the aggregate market value of the registrant's common stock held by non - affiliates was approximately $ 2,229,464,061 , based on the closing price of the registrant's common stock as reported on the New York Stock Exchange on such date . As of February 16 , 2021 , the registrant had 27,128,567 shares of common stock , $ 0.001 par value per share , outstanding . DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant's definitive proxy statement for its 2021 annual stockholders ' meeting , which is to be filed within 120 days of the registrant's fiscal year ended December 31 , 2020 , are incorporated by reference into Part III of this Annual Report on Form 10 - K .